Asterisk requires GNU C extensions. On some systems certain libraries
may incorrectly push -std=c99 into CFLAGS, thus breaking the build.
This change causes that flag to be stripped so the Asterisk build is not
broken by those libraries. This change is made for both pkgconfig and
tool based libraries.
ASTERISK-27629 #close
Change-Id: I13389613b194abbac77becf90cd950dc168704db
AST_PKG_CONFIG_CHECK: Similar to AST_EXT_LIB_CHECK, but simply uses
pkg-config data.
This simple version only uses pkg-config(1)'s tests.
This commit also uses the macro to test for GTK2 and GMIME (instead of
the current direct usage of pkg-config).
Review: https://reviewboard.asterisk.org/r/1906/
git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@366351 65c4cc65-6c06-0410-ace0-fbb531ad65f3