Fix bug 2285 (tex2lyx is not found by lib/configure when compiling with

Fix bug 2285 (tex2lyx is not found by lib/configure when compiling with
--with-version-suffix):

	* src/lyx_cb.C
	(reconfigure): get the configure command from package()

	* src/lyx_main.C
	(showFileError): ditto

	* src/support/package.[Ch]
	(configure_command): new, return the configure command

	* src/support/package.C.in
	(with_version_suffix): new, return the version suffix argument
	of the configure command

	* src/support/Makefile.am
	(package.C.in): substitute %PROGRAM_SUFFIX% in package.C.in

	* config/lyxinclude.m4: substitute program_suffix

git-svn-id: svn://svn.lyx.org/lyx/lyx-devel/trunk@13710 a592a061-630c-0410-9148-cb99ea01b6c8