Fix version number issues.

Info.plist now uses MODULE_VERSION for version number (instead of
fixed version string or non-existant CURRENT_PRODUCT_VERSION value).

Project file now defines MODULE_VERSION as CURRENT_PROJECT_VERSION
and bumps CURRENT_PROJECT_VERSION to version 0.1.1.
Remove dependence on C++11.

This enables building with older versions of Xcode.
Update project files.

Add missing project file contents.xcworkspacedata and update .gitignore
(taken from https://github.com/github/gitignore)