* configure: Drop AM_MAINTAINER_MODE
* autogen.sh: Honor NOCONFIGURE=1
* Add -version option to print program version
* Print which option was in error along with usage message
* Avoid null pointer use if malloc() fails
* Remove unneeded casts on malloc, realloc, and free calls
OBS-URL: https://build.opensuse.org/package/show/X11:XOrg/xmodmap?expand=0&rev=8