* 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
This simplifies the import process back into google3 and allows us to add additional directories to the project without needing to update the project files for each directory we add. This shows up most clearly in the change to Firestore/Example/Firestore.xcodeproj/project.pbxproj: this no longer needs to list essentially every directory in the project as a header search path.
* Clang-format configuration for C++ files
* Add support C++-only sources to the podspec
* Podspec support for fully qualified imports
* xcodeproj changes for fully-qualified imports
* Use fully-qualified imports in Firestore sources
zxu