Move osx/ to platform/osx/
Add 'osx' target in Makefile; cleanup xcode project files
Makefile: osx target now depends on the server target; Add build instructions to README
Add SQLite3 stubs; Change server config.go to export lowercase JSON fields
Remove sqlite3 support in favor of local mongodb server
Add Dashboard tab in OSX app; make the app focus the Preferences window; begin adding Local user authentication