#27 STM32F7 support

[Tomasz Jakubek]

Hi,
it's time for my input into the development of EmbSysRegView. Attached please find a patch with all my changes.
Changelist:

1. Added:
   ./STM32F7x2.svd
   ./STM32F7x2.xml
   ./STM32F7x3.svd
   ./STM32F7x3.xml
   ./STM32F7x5.svd
   ./STM32F7x5.xml
   ./STM32F7x6.svd
   ./STM32F7x6.xml
   ./STM32F7x7.svd
   ./STM32F7x7.xml
   ./STM32F7x9.svd
   ./STM32F7x9.xml
   Each pair contains exactly the same files, only different file name extension (seems this is convention).
2. Updated 'Contents.txt'