add libs/precompile-lib.xtm

Squashed commit of the following:

commit 961d8cc48ca452f81db5752a7eee7f3b417fd91a
Author: Ben Swift <benjamin.j.swift@gmail.com>
Date:   Fri Jun 20 14:43:46 2014 +1000

    add return val argument to exit

commit 947e10a2cf897c4bcbfb1ebbf1141099e9766714
Author: Ben Swift <benjamin.j.swift@gmail.com>
Date:   Fri Jun 20 14:36:29 2014 +1000

    precomp lib file works on math.xtm

commit 3479e67ca87e60207e0cec133fd67b5864a5e740
Author: Ben Swift <benjamin.j.swift@gmail.com>
Date:   Fri Jun 20 12:27:56 2014 +1000

    bugfix

commit 26bfc123fffa54516e2af618984086889bc65c28
Author: Ben Swift <benjamin.j.swift@gmail.com>
Date:   Fri Jun 20 11:57:07 2014 +1000

    move the suppress-compiler-output checks inside the log functions

    for precomp purposes

commit 402bf2c880c8f41c66b91a5ccf2e0bdc1d9a6232
Author: Ben Swift <benjamin.j.swift@gmail.com>
Date:   Fri Jun 20 10:21:53 2014 +1000

    bugfix for precomp stuff

commit 947518231c8f21649a15a9f1bb1f3d663d528a29
Author: Ben Swift <benjamin.j.swift@gmail.com>
Date:   Fri Jun 20 10:21:39 2014 +1000

    update Complex tests

commit 9684120b05b9a311a51f3c6b66c28e7473ee456c
Author: Ben Swift <benjamin.j.swift@gmail.com>
Date:   Thu Jun 19 16:51:19 2014 +1000

    WIP

commit e306d14fc3536eaf12eb13bec27b191abd2cfffc
Author: Ben Swift <benjamin.j.swift@gmail.com>
Date:   Thu Jun 19 16:29:12 2014 +1000

    precomp header file generated, but dylib doesn't load

commit 3617bbd074785b423a67393c7094ecdad700902a
Author: Ben Swift <benjamin.j.swift@gmail.com>
Date:   Thu Jun 19 14:37:17 2014 +1000

    update sys:precompile-current-module