Add Crashlytics crash handling framework and integration. Closes #139
build Hammerspoon and extensions using gyp
add howto build from source
replace external gyp dependency with inplace gyp submodule
move lua and Sparkle to third_party folder
adjust gitignore files for Xcode projects
remove remaining CocoaPods files
remove Hammerspoon Xcode project and workspace
remove extension Makefiles
add crashlytics support
move Crashlytics to third_party folder