Added external script loading.
Refactored script processing and running.
Minor clean-up.
Refactored script processing.
Added link to contribution guidelines.
Added static code analysis.
Changed the way IFile.OpenWrite works.
Added overloads for script alias methods. Closes #34.
Added support for running custom processes. Closes #71.
Added missing attributes.
MSBuild runner now uses latest MSBuild version if not explicitly specified. Closes #27.
Tweaked links in readme.

Corrected milestones link.
Changes wiki to Documentation link, since wiki currently just points to
the documentation.
Merge pull request #90 from RichiCoder1/documentation/Readme_Update_Milestone_Wiki

Tweaked links in ReadMe.
Moved Tool<T> to Cake.Core. Closes #91.
Fix for reporting exceptions.
Ignored errors are now logged.
Added GetEnvVar helper.
Expanded NUnit Settings.

Added Results File, Framework, Include, Exclude, Timeout, NoThread,
NoLogo, StopOnError, and Trace options.

Added NoResults and slightly expanded tests.
Merge pull request #87 from RichiCoder1/feature/Expand_NUnit_Settings

Expanded NUnit Settings.
Added HasEnv() and Tests.