rwlock upgrade does not work correctly in all cases

git-svn-id: https://svn.code.sf.net/p/chan-sccp-b/code/trunk@5019 43c1dc8c-776e-4df2-8ef1-6e829299be21
rwlock upgrade does not work correctly in all cases (remove debug logging)

git-svn-id: https://svn.code.sf.net/p/chan-sccp-b/code/trunk@5020 43c1dc8c-776e-4df2-8ef1-6e829299be21
Fix rwlock re-entrancy issue during module unload

git-svn-id: https://svn.code.sf.net/p/chan-sccp-b/code/trunk@5021 43c1dc8c-776e-4df2-8ef1-6e829299be21
Use pbx_mutex_t / pbx_rwlock_t instead of ast_mutex_t / ast_rwlock_t in all instances (to enable the possibility of debugging when necessary / no lock debugging enabled by default)

git-svn-id: https://svn.code.sf.net/p/chan-sccp-b/code/trunk@5022 43c1dc8c-776e-4df2-8ef1-6e829299be21