Remove all source files exclusive to Arm Compiler and IAR (#159) ...

* Remove all source files exclusive to Arm Compiler and IAR

* Also remove 'TOOLCHAIN_ARM'

* Remove targets.json entries for ARM and IAR

Refactor upload methods to streamline the debugging experience (#129) ...

* Change all debug configurations to not reset and exit on error.  Initial tasks.json implementation.

* st-util working on command line and VS Code!

* Convert STM32CUBE, fix spaces in GDB server task command

* pyocd working!

* Convert OpenOCD

* Convert JLINK

* Convert REDLINK upload method

* Fix CMake typo

* Try and fix some variable scope issues

* Initial CLion implementation.  Need to test with hardware.

* Add a separate task that kicks off a build before each debug session

Enable disabling target files for custom targets (#107) ...

* Enable disabling target files for custom targets

* Fix unittests

* Fix unittests again

add custom linker script (#103) ...

* add custom linker script
a custom linker script can be applied by adding the .ld filepath
as 2nd argument to mbed_set_post_build

* more detailed comment

* add if is_standalone for text cases

* replace COMMENT in add_custom_command by echo
COMMENT is not reliable printed

add depth, json and html to memap (#95)

Don't use whole-archive linking (#71) ...

* First attempt at converting to OBJECT libraries.  Not working due to more object library limitations

* Only compile the main libraries as OBJECT, because that's all that CMake can be made to do right now.

* Fix availability of target-specific flags

* Missed some usages

* Fix some STM32 ethernet stuff that was not linking correctly

* More fixes for STM32 ethernet and weak symbols

* Fix prebuilt object file linking for MUSCA_S1

* Fix STM32 eth init license headers