FS-6293: fix srcdir build for mod_opus
Edit out gcc-ism from soundtouch lib

This allows building mod_soundtouch in clang as clang doesn't support
gcc's -fcheck-new.
FS-6293: fix mod_xml_rpc srcdir build
lets just consistently use api for version
Build openldap with -j1

Things seem to go wrong when building mod_ldap with make -j.
FS-6293: fix mod_skypopen srcdir build