Project references can lock output assembly file and prevent compilation

[ramon-rocha]

Due to the way the add-in builds the AST (via Cobra.Compiler.dll), a project reference will lock the output file and prevent further compilation of the referenced project.

We'll need a non-locking library reading mechanism in the short term and a separate way to build the AST in the long term.

See here for more information: http://cobra-language.com/forums/viewtopic.php?p=22528#p22528