Move define to CPPFLAGS in mod_h323
Remove ptlib include in mod_h323

This doesn't seem needed, and the empty include was breaking the
build.
Move mod_h323 -fno-exceptions flag to CXXFLAGS
Reorder lines in mod_h323 build
FS-6293: fix mod_spidermonkey srcdir build
Use $(shell) make function in mod_opal
Fix mod_opal build

...by separating out CPPFLAGS and CXXFLAGS.