[LPC1549] Added USBDevice support

[LPC1549] Added USBDevice support by va009039's code
[LPC1549] Fixed warnings by GCC toolchain and removed redundant code
[LPC11U68] Fixed warnings by GCC toolchain and removed redundant code
Merge pull request #360 from toyowata/master

[LPC1549] USBDevice support
Fix compiler warning (signed vs. unsigned comparison).
Fix compiler warning (signed vs. unsigned comparison).
[NUCLEO_F411RE] Add uVision4 exporter
Merge pull request #366 from bcostm/master

[NUCLEO_F411RE] uVision4 exporter template
Disable rtti for gcc.
Merge pull request #368 from chrta/gcc_disable_rtti

[Exporters] Disable rtti for gcc.
Merge pull request #365 from chrta/fix_signed_unsigned_compare

Fix signed unsigned compare in dsp library