BOO-914: Extract Macros and Attributes from the Boo.Lang.Compiler into Boo.Lang.Extensions
* Preparation for moving AST to Boo.Lang.Ast
* Move MetaAttribute to Boo.Lang
* Moved Compilation.cs up to root, elminating MetaProgramming folder of Boo.Lang.Compile
* Moved AST Attributes and Macros to Boo.Lang.Extensions
* Corrected Boo.NAnt.Tasks since it cannot depend upon Boo.Lang.Extensions
* Compiler uses Boo.Lang.Extensions if it exists, otherwise skips it
* Added Boo.Lang.Extensions as a default namespace
* Corrected a couple of tests/test fixtures
* Running "nant test" from root directory is broken
** You can still run tests by changing to "tests" directory and running "nant"
** Workaround available in root default.build in XML comments
** Caused because of AppDomain spoilage when moving between /build and /tests/build
*** build/Boo.Lang.Compiler and build/Boo.Lang stay in memory
*** This causes some resolutions to be split between /build and /tests/build
git-svn-id: https://svn.codehaus.org/boo/boo/trunk@2765 2c1201b4-01cd-e047-a400-b836ae1fbc61