Flipper Release: v0.15.0

Summary:
- Added build-headless yarn target for producing a headless binary
- Crash Reporter plugin added. Details [here](https://fbflipper.com/docs/crash-reporter-plugin.html).
- Bug fixes and dependency updates

- Desktop notifications for all kinds of crashes with their callstack
- Desktop notifications when an exception occurs within [Litho's error boundaries](https://fblitho.com/docs/error-boundaries)
- Ability to deeplink to the crash entry in the Logs plugin for Android. This feature is not available in iOS as the callstack doesn't get logged through Flipper's Logs plugin
- Ability to copy the stacktrace by right-clicking it
- Ability to see the list of crashes in the Notifications hub

Reviewed By: passy

Differential Revision: D13880665

fbshipit-source-id: 92a3455bb826b6fb22858e2c4c88c0b9ace91a5f

Specs/Flipper/0.15.0/Flipper.podspec

@@ -0,0 +1,24 @@
+flipperkit_version = '0.15.0'
+Pod::Spec.new do |spec|
+  spec.name = 'Flipper'
+  spec.version = flipperkit_version
+  spec.license = { :type => 'MIT' }
+  spec.homepage = 'https://github.com/facebook/sonar'
+  spec.summary = 'SonarKit core cpp code with network implementation'
+  spec.authors = 'Facebook'
+  spec.source = { :git => 'https://github.com/facebook/Sonar.git',
+                  :tag => 'v'+flipperkit_version }
+  spec.module_name = 'Flipper'
+  spec.public_header_files = 'xplat/Flipper/*.h','xplat/utils/*.h'
+  spec.source_files = 'xplat/Flipper/*.{h,cpp,m,mm}','xplat/Flipper/utils/*.{h,cpp,m,mm}'
+  spec.libraries = "stdc++"
+  spec.dependency 'Folly', '~>1.2'
+  spec.dependency 'RSocket', '~>0.10'
+  spec.compiler_flags = '-DFLIPPER_OSS=1 -DFB_SONARKIT_ENABLED=1 -DFOLLY_NO_CONFIG -DFOLLY_MOBILE=1 -DFOLLY_USE_LIBCPP=1 -DFOLLY_HAVE_LIBGFLAGS=0 -DFOLLY_HAVE_LIBJEMALLOC=0 -DFOLLY_HAVE_PREADV=0 -DFOLLY_HAVE_PWRITEV=0 -DFOLLY_HAVE_TFO=0 -DFOLLY_USE_SYMBOLIZER=0 -Wall
+    -std=c++14
+    -Wno-global-constructors'
+  spec.platforms = { :ios => "8.0" }
+  spec.pod_target_xcconfig = { "USE_HEADERMAP" => "NO",
+                               "CLANG_CXX_LANGUAGE_STANDARD" => "c++14",
+                               "HEADER_SEARCH_PATHS" => "\"$(PODS_TARGET_SRCROOT)\" \"$(PODS_ROOT)/boost-for-react-native\" \"$(PODS_ROOT)/RSocket\" \"$(PODS_ROOT)/DoubleConversion\"" }
+end