STM32f103c8 board

I fixed some basic errors on the board:

• Capacitors more close to the STM32
• VBAT connected
• VSSA connected to ground
• VDDA connected to VCC

I added a new layout 10cm x 8cm and sent it to a cheap Chinese PCB lab. I will upload some photos when receive it.

• Removed UART pins
• UART1 RX and TX are routed only in CH340G
• CAN changed to alternative pins in order to avoid USB sharing
• Added again ground planes

• Revision 5 with better layout, pullup in USB+ and a CH340G.
• Still missing a better solution with shared lines in CAN and programming USB.
• Ground planes removed.

Added CH340G to UART1 for firmware burning through STM32F bootloader.