Add overload for file globbing

This is just an initial spike to see if this fits into the pattern
Add minimatch and use for globbing
Output, error handling
Merge branch 'file-globbing' of https://github.com/msarchet/pvc
Consistency fix for output
Made glob search recurse and use relative paths for matching. Moved Minimatch to Lib folder.
Fixed issue with non-globbed paths in Source, added FindBinaryInPath util method, throw on Compile errors from scriptcs
Cleaned up exception when task not found, added Core pvcfile.csx, added proper assembly loading to scriptcs execution
Fix for stupidity
Fix for PvcPlugins namespace issue in CLI
Updates to README
Added plugin level namespace registration, moved PvcPlugin to PvcPlugins namespace
Modified plugin API to allow for plugin provided using statements, switched to loading packages from pvc-packages instead of packages
Added support for pvc-packages/, pvc-packages/pvc-packages.config and updated README
Incremented Core version to 0.0.1.3, CLI to 0.0.1.2
Installer and arg parsing
Lazy stream creation, OriginalSourcePath added to streams. Fixes #15.
Simple scripted plugins inside pvcfile. Fix task execution arg processing. Closes #66.
Changed FilterPaths options, added basic unit tests to monitor this. Fixes #17. Closes #7.
Matching on tags in pipeline for execution. Closes #14.