Add TARGET_STM32F4 folder with STM32Cube driver inside
Put NUCLEO_F401RE specific files
Put NUCLEO_F411RE specific files
Remove misplaced F401RE folder
Remove misplaced F411RE folder
[DISCO_F334C8] new target incl. rtos support

New target as a copy of nucleo_f334 with changes/additions in pin and
rtos definitions.
[BUILD_TRAVIS.py] additional line for disco_f334

Adding a line for disco_f334 target and adding the rtos lib to
nucleo_f334 target.
[BUILD_TRAVIS.py] additional line for nucleo_l053

Adding a line for nucleo_l053 target.
[TARGET_STM32F4] new structure for F407 and F429 targets -part1

move specific files from old position into new target folders under
target_stm32f4
[TARGET_STM32F4] new structure for F407 and F429 targets - part2

remove target_stm32f407vg files
[TARGET_STM32F4] new structure for F407 and F429 targets - part3

remove target_stm32f429zi files
[TARGET_STM32F4] new structure for F407 and F429 targets - part4

Solves the problem NULL -> HAL_NULL for the additional hw blocks in the
larger mcus.

For F401 and F411 this was already solved in #596.
Reorganisation of NUCLEO_L053R8 and DISCO_L053C8 cmsis folders  - part1

Delete cmsis files of disco_l053c8
Reorganisation of NUCLEO_L053R8 and DISCO_L053C8 cmsis folders  - part2

Deletes cmsis files of nucleo_l053c8
Reorganisation of NUCLEO_L053R8 and DISCO_L053C8 cmsis folders  - part3

Moves target/toolchain specific files to new location
Reorganisation of NUCLEO_L053R8 and DISCO_L053C8 cmsis folders  - part4

Moves cmsis files to new location.
remove un-unsed variables.
Getting rid of some compiler warnings.
white space diffs.
[NUCLEO_F334R8] Add IAR exporter
[MAKE.py] [BUILD.py] some minor

Ordering the entries in mcu and toolchain lists when printing the help
text.