Fixed MIP encoding issues with holes in domains and reification of some constraints.
Squashed commit of the following:

commit 2c644f5cd72dd72eba87989185c8a6ef576c6005
Author: 9thbit <9thbit@gmail.com>
Date:   Sun Jan 13 17:55:41 2013 +0000

    Turn off debug symbols and turn on optimisation in MIPWrapper makefile.
    Makefile fix for clean_all in SCIP

commit 49d32485d6a13d416b7eda080291531592065c8e
Author: 9thbit <9thbit@gmail.com>
Date:   Sun Jan 13 17:28:32 2013 +0000

    Add support for reification of disquality constraint between variable and value.

    TODO: reification of disequality between two variables.

commit e3abe9878da9ff48aa8edbe5f2e3d71cf1c88fcf
Author: 9thbit <9thbit@gmail.com>
Date:   Sun Jan 13 17:25:46 2013 +0000

    Fixed a bug where an equality between a variable and a value that is not in its domain, did not result in a constraint being added.

commit 3a44248793fbc45df9db3d99932416fc8fbd3041
Author: 9thbit <9thbit@gmail.com>
Date:   Sun Jan 13 15:37:11 2013 +0000

    Spelling corrections in debug messages.

commit 6c4564f98b3805cf5c95889828c4f18613b1d4ee
Author: 9thbit <9thbit@gmail.com>
Date:   Sun Jan 13 15:36:51 2013 +0000

    Fixed a few bugs encoding domains with holes to MIP.