API changes

• Ignore
  • Made Ignore.pathIsIgnored async PR #970

Bug fixes

• Added an error message when trying to install NodeGit without a required version of libstdc++ PR #972
• Fix a crash when grabbing content out of a buffer that has unicode PR #966
• Added some plumbing for better memory management PR #958
• Fix checkoutOptions in Stash#apply PR #956
• Fixed install when there is a space in the username on windows PR #951
• Bump to nan@2.2.0 PR #952