Fix gdb and flash support for the STM32F769I-Disco board.

Fix an erase error in stm32f030 device.

I run into flashing error with stm32f030. With some
debugging I find out that the mass erase bit was dropped
when flash programming bit already set on FLASH_CR.
This cause erase and write error with my stm32f030
board.

Mass erase never need the programming bit. Turn off the
programming bit make stlink flash stm32f030 successfully.

Fix a regression introduced in 71535104.

Since STLINK V1 cannot read voltage, and attempting to do so breaks the
USB communications, this patch will revert the behaviour to just blindly
doing 32-bit writes on these programmers.

Support stm32f7x7x, fixes #433 

* 'master' of github.com:texane/stlink:
  Update README

Add notice about broken stlink firmware V2.J16.S0 on STM32 L1 Discovery board

Add a useful error message instead of "[!] send_recv"

Don't read the target voltage on startup, because it crashes STM32F100.

WIP: Fix compiler warnings

 - Replace 'typedef reg' by 'struct stlink_reg'
 - Prefix the 'sl' global variable with a 'g'
 - Rename 'j' -> 'k' and 'i' -> 'j' variables
 - Rename 'hex' variable into 'hextmp'
 - Fix unused parameter
 - Use a correct printf format for gsize
 - Use correct MAX macro
 - Use correct data casting
 - Do not use 'GTK_STOCK_*' anymore
 - Do not use 'gtk_tree_view_set_rules_hint'
 - Remove unused functions
 - Explicitly cast data type
 - Enable Werror

Related to https://github.com/texane/stlink/issues/356

* 'master' of github.com:texane/stlink:
  travis: Add gcc-5 and clang-3.8 to matrix for linux cmake builds

travis: Add gcc-5 and clang-3.8 to matrix for linux cmake builds

cmake: Search for static libusb-1.0 library on OSX and link with ObjC,CoreFoundation and IOKit frameworks

logging.h: Add helpers so the log macros can have just one argument, needed for compilation on visual studio

Fix const warning on struct stlink_chipid_params

Fix link to UweBonnes/wiki_fuer_alex

Add Contributing and versioning to README

stlink_gui: Fix compiler warning on overflow