Release 3.6.0: F030 support

I'm happy to announce the 3.6.0 release of stm32plus featuring support for the low-cost F030 Cortex-m0 line (big thanks to @joaoc for contributing this feature). This will probably be the last 3-point-something release before the major 4.0.0 release that will support the most popular USB device classes on the F4. More on that later, but now let's see what we've got in 3.6.0:

Typo fix and addition of STM32F030: #78
The headline feature for this release. The scons mcu target name is f030, for example: scons mode=small mcu=f030 hse=8000000.

Upgrade f4 std peripheral lib to 1.4.0 and support all F4 variants: #64
Adds explicit support for many more F4 variants via the scons build. In practice I expect most people to carry on using mcu=f4 which is now an alias for mcu=f407.

EXTI line 13 interrupt problem: #79
Fix a problem affecting port C EXTI interrupt support on the f0 and f4 whereby the SYSCFG clock was not enabled.

SDIO driver does not support 16Gb+ card capacities: #77
ST demonstrate that they don't really understand how the C language works :(

Cannot remap USART1,2,and 3 on STM32F1 series: #74
Important fix for USART users on the F1 series.

Found a mistake in include/traits/f1/cl/traits.h: #71
Removed some unused code.

F4 OTG FS Wakeup IRQ handler name incorrect: #70
We'll need this fix for the next release.

Exti IRQ handler gets garbage collected by the linker: #69
gcc gets a bit over-zealous with its garbage collection algorithm.

Expose remote address of received UDP datagrams: #68
Add commonly required functionality to the network stack.

net_udp_receive_async doesn't clear data arrived flag on startup: #67
Bug in one of the examples.