[NUCLEO_F401RE] Fix issue with sleep and ST HAL tick timer

The timer used for the ST HAL tick must be disabled before entering in
sleep mode.
[NUCLEO_F072RB] Add assert
[DISCO-F303VC] Updated with F302R8 recent changes
[DISCO-F051R8] Updated with F030R8 recent changes
Merge pull request #374 from bcostm/fix_F401RE_sleep

[NUCLEO_F401RE] Fix issue with sleep and ST HAL tick timer
Merge pull request #375 from bcostm/dev_F072RB_assert

[NUCLEO_F072RB] mbed assert addition
Merge pull request #378 from dinau/disco_f051r8_update

[DISCO-F051R8] Updated with F030R8 recent changes
Merge pull request #377 from dinau/disco_f303vc_update

[DISCO-F303VC] Updated with F302R8 recent changes
Added TODO to fix issues with serial detection
Added option -c to control how we are going to copy files on target platform disk
Added more todo to host test file
Merge branch 'master' of https://github.com/mbedmicro/mbed