Add missing short descriptions, standardize them to start with a capital

* gobject/tmpl/gclosure.sgml:
	* gobject/tmpl/signals.sgml:
	* gobject/tmpl/gparamspec.sgml:
	* gobject/tmpl/value_collection.sgml:
	* gobject/tmpl/generic_values.sgml:
	* gobject/tmpl/param_value_types.sgml:
	* gobject/tmpl/gboxed.sgml:
	* gobject/tmpl/enumerations_flags.sgml:
	* gobject/tmpl/objects.sgml:
	* gobject/tmpl/gtypemodule.sgml:
	* gobject/tmpl/gtypeplugin.sgml: Add missing short descriptions,
	standardize them to start with a capital and end without a period.

	* glib/tmpl/arrays.sgml:
	* glib/tmpl/memory_chunks.sgml:
	* glib/tmpl/macros.sgml: Remove periods from titles in examples.

docs/reference/gobject/tmpl/enumerations_flags.sgml

@@ -2,7 +2,7 @@
 Enums and Flags
 
 <!-- ##### SECTION Short_Description ##### -->
-Enumeration and flags types.
+Enumeration and flags types
 
 <!-- ##### SECTION Long_Description ##### -->
 <para>

docs/reference/gobject/tmpl/gboxed.sgml

@@ -2,7 +2,7 @@
 GBoxed
 
 <!-- ##### SECTION Short_Description ##### -->
-Mechanism to wrap opaque C structures registered by the type system.
+A mechanism to wrap opaque C structures registered by the type system
 
 <!-- ##### SECTION Long_Description ##### -->
 <para>

docs/reference/gobject/tmpl/gclosure.sgml

@@ -2,7 +2,7 @@
 Closures
 
 <!-- ##### SECTION Short_Description ##### -->
-
+Functions as first-class objects
 
 <!-- ##### SECTION Long_Description ##### -->
 <para>

docs/reference/gobject/tmpl/generic_values.sgml

@@ -2,7 +2,7 @@
 Generic Values
 
 <!-- ##### SECTION Short_Description ##### -->
-A polymorphic type that can hold values of any other type.
+A polymorphic type that can hold values of any other type
 
 <!-- ##### SECTION Long_Description ##### -->
 <para>

docs/reference/gobject/tmpl/gparamspec.sgml

@@ -2,11 +2,11 @@
 GParamSpec
 
 <!-- ##### SECTION Short_Description ##### -->
-Meta data object for parameter specifications.
+Metadata for parameter specifications
 
 <!-- ##### SECTION Long_Description ##### -->
 <para>
-#GParamSpec is an object structure that encapsulates the meta data
+#GParamSpec is an object structure that encapsulates the metadata
 required to specify parameters, such as e.g. #GObject properties.
 </para>
 
@@ -69,7 +69,7 @@ Retrieve the #GParamSpecClass of a #GParamSpec.
 
 <!-- ##### MACRO G_PARAM_SPEC_TYPE ##### -->
 <para>
-Retrive the #GType of this @pspec.
+Retrieve the #GType of this @pspec.
 </para>
 
 @pspec: a valid #GParamSpec
@@ -77,7 +77,7 @@ Retrive the #GType of this @pspec.
 
 <!-- ##### MACRO G_PARAM_SPEC_TYPE_NAME ##### -->
 <para>
-Retrive the #GType name of this @pspec.
+Retrieve the #GType name of this @pspec.
 </para>
 
 @pspec: a valid #GParamSpec
@@ -85,7 +85,7 @@ Retrive the #GType name of this @pspec.
 
 <!-- ##### MACRO G_PARAM_SPEC_VALUE_TYPE ##### -->
 <para>
-Retrive the #GType to intiialize a #GValue for this parameter.
+Retrieve the #GType to intiialize a #GValue for this parameter.
 </para>
 
 @pspec: a valid #GParamSpec

docs/reference/gobject/tmpl/gtypemodule.sgml

@@ -2,7 +2,7 @@
 GTypeModule
 
 <!-- ##### SECTION Short_Description ##### -->
-Type Loading Modules
+Type loading modules
 
 <!-- ##### SECTION Long_Description ##### -->
 <para>

docs/reference/gobject/tmpl/gtypeplugin.sgml

@@ -2,7 +2,7 @@
 GTypePlugin
 
 <!-- ##### SECTION Short_Description ##### -->
-
+An interface for dynamically loadable types
 
 <!-- ##### SECTION Long_Description ##### -->
 <para>

docs/reference/gobject/tmpl/objects.sgml

@@ -2,7 +2,7 @@
 GObject
 
 <!-- ##### SECTION Short_Description ##### -->
-The base object type.
+The base object type
 
 <!-- ##### SECTION Long_Description ##### -->
 <para>

docs/reference/gobject/tmpl/param_value_types.sgml

@@ -2,7 +2,7 @@
 Parameters and Values
 
 <!-- ##### SECTION Short_Description ##### -->
-Standard Parameter and Value Types.
+Standard Parameter and Value Types
 
 <!-- ##### SECTION Long_Description ##### -->
 <para>

docs/reference/gobject/tmpl/signals.sgml

@@ -2,8 +2,7 @@
 Signals
 
 <!-- ##### SECTION Short_Description ##### -->
-Signals provide a means for customization of object behaviour and are used
-as general purpose notification mechanism.
+A means for customization of object behaviour and a general purpose notification mechanism
 
 <!-- ##### SECTION Long_Description ##### -->
 <para>

docs/reference/gobject/tmpl/value_collection.sgml

@@ -2,7 +2,7 @@
 Varargs Value Collection
 
 <!-- ##### SECTION Short_Description ##### -->
-
+Converting varargs to generic values
 
 <!-- ##### SECTION Long_Description ##### -->
 <para>