Find binary using the registry on Windows

- As a side effect, normalizeBinary() now returns a promise instead of
  a string
- Change runner to adapt to normalizeBinary() being async
- Add tests and change old tests
- Fallback to reading env var when registry access fails
Use path.join correctly in binary finding test. Refactor test
Style fixes, use done.bind instead of a wrapper
Style fixes
Remove the master promise variable for readability
Merge pull request #126 from XrXr/windows-binary-finding

Find binary using the registry on Windows r=@erikvold
Increment to v0.0.11
Merge pull request #129 from jsantell/master

Increment to v0.0.11
Log XPI additions in verbose
Merge pull request #131 from jsantell/log-xpi-additions

Log XPI additions in verbose, fixes #128
Log how much time it takes to build the xpi
Merge pull request #132 from jsantell/log-xpi-time

Log how much time it takes to build the xpi, fixes #127
Firefox Process now streamable, updated error reporting
Merge pull request #134 from jsantell/stream-firefox

Firefox Process now streamable, updated error reporting, fixes #130, #133
Release 0.0.12
"Foxed" typo in readme
Merge pull request #136 from spite/master

Fixed Firefox name in command
Using semver for toolbar-api example
test files were being skipped during jpm test
Bug 1042239 using promise which resolves when the system has started