Release 6.3 - update

Updating to gcc 5.3, boost 1.60 and MySQL 5.7.10

go 1.5.1 and gcc 5.2

Some cleanup for new environment, no functional changes

6.1

Move to cmake/MSYS2/MINGW64 and MySQL 5.6.26. No functional changes.

6.0

Code moved to VS 2012, MySQL 5.6.23, zlib 1.2.8 and boost 1.57.0
Default inpx-format is now 2.x

5.52.1

Introduced libget2 with SOCK5 support (including authentication for TOR and VPN downloads)