Support for STM32L4, SM32L1 option bytes write.

CKS32-Clone-Patch broke flashing on STM32 F3xx, F4xx and L1xx. (#761)

add win32 travis build

* add mingw64 build to travis CI

* Make .travis-lin-mingw.sh executable

* .travis-lin-mingw.sh: make build dir

* show $PWD in travis-lin-mingw

* update .travis-lin-mingw.sh

* ---

* update .travis-lin-mingw.sh

* update p7zip cmd

* fix sign/unsign comparioson in usb.c

* revert call .travis.sh

* clean up .travis-lin-mingw.sh

General project update & interim status of develop branch.

- Fixes in CHANGELOG.md
- Added note in README.md
- Updated package requirements.

Resolved conflicts with develop branch.

- Corrected CHANGELOG.md
- Added comment in .travis.sh
- Update for .travis.yml: gcc/g++ v5->v6

# Conflicts:
#	include/stlink/chipid.h
#	src/chipid.c

Fixed stlink support with no mass storage (#861).

Add aliased SRAM2 region in the L496 memory map (#824)

[doc/trivial] Fix st-flash manpage read example (#858)

-> CKS devices with Core ID 0x2ba01477
(Closes #756 #757 #761 #766 #769 #805)

- Updated README & CHANGELOG.
- Updated issue templates.
- Fixes in travis.yml

added several comments on the stlink software structure

Fix dead link in README.md