Remove CHECK_AUTOCONF, as AC_PREREQ does the same thing
Move CHECK_CPPUNIT code directly into configure.ac for stability/path issues
More concise CHECK_SSL
Remove redundant CHECK_RT code
Remove redundant CHECK_XERCES
Remove redundant CHECK_APACHE2
Remove redundant CHECK_MODCPLUSPLUS
Use pkg-config to find libpcre
Use ustar format for tar due to long filenames
Adjust version, building pre-releases for 3.3.0
Update for spandsp includes
Eliminate plgilbc hard dependency on contrib ilbc
Eliminate dependency on contrib for build, leave it out of dist