Bug 940167 - More specificity for which mappings might be libraries on B2G. r=BenWa

Note that we don't want this extra check on regular Android, because
there's Dalvik jitcode in ashmem, and any mappings that aren't that
special ashmem file will already be excluded (because everything else is
handled through dl_iterate_phdr).
Bug 934000 - Minor SMS bugfixes. r=mrbkap
Bug 935118 - Allow buffering to be triggered when we're low on decoded audio or video. r=roc