* implement Firestore DatabaseInfo in C++
* temporary stash changes; blocking on the massive renaming of .m to .mm
* add database_info_test to project
* finish port DatabaseId and fix style, modular fixing DatabaseInfo
* port DatabaseInfo
* remove FSTDatabase{ID,Info} and their tests from project
* fix unit test
* use namespace alias
* use namespace alias, leftover
* address more changes
* refactoring to use raw pointer instead of value for property
* address changes
* remove self->
* fix style
* remove the name suffix Alloc
* fix a bug
* Replacing FIR_SWIFT_NAME macro with NS_SWIFT_NAME.
This pushes the minimum Xcode version to 7.3, as NS_SWIFT_NAME was
limited before that version (which is why the macro was introduced in
the first place).
* Fixed FIRMessaging header
zxu