package qtbase: disable mysql detection

fixes #325
mxe-activate: fix tools path and target list
doc update: note that MXE is not relocatable
Merge branch 'stable'
package opencv: update and enable i686-w64-mingw32
package mingw-w64: workaround for -isystem flag messing up include order
package opencv: fixes for i686-pc-mingw32 and x86_64-w64-mingw32
doc update: improve naming of MAXR
doc update: add Galois to the list of projects which use MXE
Merge branch 'stable'
Revert "doc update: improve naming of MAXR"

This reverts commit e46546cae0b6288fadaadf8c7d532e9faf58d0a2.
Merge branch 'stable'
Merge remote-tracking branch 'upstream/master'