Add github.ReportCrash to send user errors.
Simplify title and body hint message creation.
Generate crash report editor message.

- Check report crash option saving.
Merge branch 'master' into crash_report

* master: (70 commits)
  Explicitly build to gh
  Don't use we
  Add instruction for building gh from source
  Update README to install/update from source
  Fix bug that it doesn't update if timestamp is invalid
  Test unzipExecutable
  Pass in DefaultHost from NewUpdater
  Add test to downloadFile
  Use stub credentials for update client
  Move client init down close to use
  Make anonymous gh update possible
  Remove logs.
  Make sure we test against a good version of git.
  Import fmt.
  Log the submodule process.
  Announce step to see what travis is executing.
  Remove @wip from `submodule add`.
  Revert "Remove @wip from `submodule add`."
  Remove @wip from `submodule add`.
  Be more explicit on API error message
  ...

Conflicts:
	commands/pull_request.go
	commands/release.go
	github/editor.go
Move the crash report to the new editor.
Report error, stack and runtime information.
Add error type to the report.
Capture panic errors and notify them as unexpected crashes.
Do not modify fatal output.
Make gh project info constant.
Check string errors.
Remove nesting.
Add crash reporting to the readme.
Use git's global config to store the crash report configuration.
Merge branch 'master' into crash_report

* master:
  Generate man page for gh
  Bump homebrew-gh

Conflicts:
	README.md
Add test for the new git config functions.
Merge pull request #135 from jingweno/crash_report

Add crashing reports.