fixed fpu parameters in NUCLEO and STM32F407 -device.mk files
Update Cortex-M4F -device.mk files

The C_FLAGS, ASM_FLAGS, and LD_FLAGS all need to contain the following
CPU/FPU options to fully select the type of device the code is being
built for:
    -mcpu=cortex-m4 -mthumb -mfpu=fpv4-sp-d16 -mfloat-abi=softfp
For the compiler, these flags indicate the type of code it should
generate.  For the linker, the flags indicate which standard C/C++
library version should be pulled from the multi-lib.
Add rtos_basic sample from mbed site

I pulled this RTOS sample from
  https://developer.mbed.org/teams/mbed/code/rtos_basic/

I added it since I recently broke building of RTX for Cortex-M0+ parts
such as the KL25Z and didn't notice since only some LPC1768 samples
were previously making use of the RTOS.

Thanks to @rosterloh for pointing this issue out:
https://github.com/adamgreen/gcc4mbed/issues/20
Fix for issue #20

When filtering out unsupported TARGET_M0 targets, it was also filtering
out the desired TARGET_M0P target.

The filtering is now peformed with the */TARGET_XX/* pattern instead of
the previous */TARGET_XX* pattern previously used.  This did require
placing a trailing slash on the input directory names just before
performing this pattern match and then removing it immediately
thereafter since the rest of the code doesn't want the trailing
slashes.
Merge branch 'working' of https://github.com/svkatielee/gcc4mbed into working

Conflicts:
	build/DISCO_F407VG-device.mk
	build/NUCLEO_F401RE-device.mk
fix LD_FLAGS