Subject: Fix gcc6 build failure

Taken from fedora.

---
diff -up LibreCAD-dbf1cc7c9597740d34a068f6f09c36841054e903/librecad/src/boost.pri.gcc6 LibreCAD-dbf1cc7c9597740d34a068f6f09c36841054e903/librecad/src/boost.pri
--- LibreCAD-dbf1cc7c9597740d34a068f6f09c36841054e903/librecad/src/boost.pri.gcc6	2016-06-06 11:47:24.087659733 -0400
+++ LibreCAD-dbf1cc7c9597740d34a068f6f09c36841054e903/librecad/src/boost.pri	2016-06-06 11:47:27.439636022 -0400
@@ -113,7 +113,7 @@ unix {
     }
 
 
-    INCLUDEPATH += $${BOOST_INCDIR}
+    # INCLUDEPATH += $${BOOST_INCDIR}
     HEADERS += $${BOOST_INCDIR}
 
     !isEmpty( BOOST_LIBS ) {
diff -up LibreCAD-dbf1cc7c9597740d34a068f6f09c36841054e903/librecad/src/muparser.pri.gcc6 LibreCAD-dbf1cc7c9597740d34a068f6f09c36841054e903/librecad/src/muparser.pri
--- LibreCAD-dbf1cc7c9597740d34a068f6f09c36841054e903/librecad/src/muparser.pri.gcc6	2016-06-05 02:27:45.000000000 -0400
+++ LibreCAD-dbf1cc7c9597740d34a068f6f09c36841054e903/librecad/src/muparser.pri	2016-06-06 11:46:11.508173138 -0400
@@ -2,9 +2,7 @@
 macx|win32|equals(build_muparser, "true")|!packagesExist(muparser){
     message("Using bundled muparser")
 	MUPARSER_DIR = ../../libraries/muparser
-	DEPENDPATH += $$MUPARSER_DIR/include \
-				$$MUPARSER_DIR/src
-	INCLUDEPATH += $$MUPARSER_DIR/include
+	DEPENDPATH += $$MUPARSER_DIR/src
 	GEN_LIB_DIR = ../../generated/lib
 	LIBS += -L$$GEN_LIB_DIR -lmuparser
 	PRE_TARGETDEPS += $$GEN_LIB_DIR/libmuparser.a