* The new scanner is currently disabled and only issues a warning
for tokens that would be lexed differently.
* Special case a few common uses of ':', to limit breakage to
a manageable level.
* Remove the horribly outdated Jambase code inherited from Perforce Jam
* Update all of Boost.Build to work in the presence of the new lexer.
Various restructure of test framework handling of paths to avoid duplicate path editing which caused failed tests. Adjust many tests to deal with added subdirectories in build outputs now that toolset requirements are active.
