Bug 1026469 - Use AC_CHECK_LIB instead of MOZ_CHECK_PTHREADS. r=ted
Bug 1026469 - Update to NSPR_4_10_7_BETA1. r=ted

- Use AC_CHECK_LIB instead of MOZ_CHECK_PTHREADS. r=ted
- Skip compiler checks when using MSVC, even when $CC is not literally "cl". r=ted