arch/arm: add THUMB mode config option

arch/arm: no need to check for the ABI option

The ABI option can not be set if EABI was selected,
so no need to check for it.

arch/arm: add support for noMMU

Some ARM cores do not have an MMU (eg. Cortex-Mx and Cortex-Rx series).
Thus, allow the user to configure out the MMU for ARM.

libc/newlib: allow using CVS snapshots

The newlib "team" rolls new releases about once a year (december).
This is quite a long time between releases, in case code was fixed.
So, allow user to use a CVS snapshot to benefit early from fixes
and enhancements to newlib.

functions: allow using sub-dir of a module

Some projects' module (eg. newlib) are checked-out into a sudirectory
rather than into their own directory. Handle this case in the CT_GetCVS
function.

libc/newlib: allow using newlib with archs other than avr32

libc/newlib: fix namespace in config file

C library config options should be prefixed with 'LIBC_'.

libc/newlib: cleanup the build and finish steps

build step:
- ./configure
- remove glibc-specific options
- pass the target CFLAGS in the correct variable
- make:
- build in //

finish step:
- print proper message in finish step

libc/newlib: fix host/target confusion

newlib handles the build/host/target a bit differently as one would expect:
build : not used
host : the nachine that builds newlib
target : the machine on which newlib will run

debug/dmalloc: fix handling of threading model