Feature/pl report window

Adds a crash reporter window to PLCrashReporter in the OS X framework.

TODO: testing on iOS and with static target
TODO: documentation and integration with test app

![screen shot 2014-08-17 at 7 33 08 pm](https://cloud.githubusercontent.com/assets/53469/3964060/57eead66-2784-11e4-9f58-9a133c351157.png)

![screen shot 2014-08-18 at 12 59 49 am](https://cloud.githubusercontent.com/assets/53469/3964066/5e74b7de-2784-11e4-92ed-c1186930d9b0.png)

The ARCHS values are set explicitly such that PLCR builds consistently for all supported architectures; Xcode has become quite liberal in removing architectures from the default set, and PLCR's supported architectures are no longer included in the default architecture setting.