Merge pull request #66 from mgee/master

Make Boxed_Number utility functions const
Add boost::system to linkage to support boost 1.50. Should not cause any issue for older users of boost
Update readme.txt to readme.md for better formatting.
Add "erase" function to associative sets (maps)
Add insert and insert_ref methods to "map" types
Add ability to specify number prefixes for floating point and integers.
Prevent leaking macros #76
Add support for string::substr #75

Also add forgotten missing test for number suffixes
Correct signing and sizing of integer literals #77
Fix errors and warnings found on VisualStudio 2005
Fix compiler warning found on VS 2008 64bit
Fix function pointer issue for substr on VS 2010 32bit
Update releasenotes and version numbers for 4.1.0 release
Fix linux build error discovered with 4.0.0 release
Update for release 4.1.1
Add ability to call functions requiring arithmetic value conversions

 - Conversions are only attempted on a dispatch
 - Conversions are only attempted after a normal dispatch has failed
 - Conversions are only attempted if exactly one function matches
   the signature of the parameters passed in - excluding the mismatched
   arithmetic parameters
 - This feature should not be relied on in performance critical code
   overhead is added for each function call that requires a conversion
   to execute, see the tests performed above.
Update version to 4.2.0
Add profile for calling functions on members of a heterogeneous array
Add unit test of suffixed number inside of vector initialization
Add 'continue' command for loops. Also enhance for() unit tests which are now breaking and need to be fixed