Added Windows installation information into README
[stm32l1] Update linker scripts

Add the M+ and H density parts, and include the EEPROM sizes
[stm32-l1] Turn on the DMA code.

It appears to be the same dma peripheral as in the F1 and F3, so just
enable it as is.
Documentation structures added to place the non-STM32 families into the documentation tree.
Actual documentation has not been added. Volunteers?