conf for Qt 5.3.1 with source depexts
disable depext packages
XCB packages for Qt compilation
opam recipe was written wrong
Add OCaml version constraint to do less builds on CI
More libxcb dependencies from qtbase/src/plugins/platforms/xcb/README (specific for Ubuntu 12.04)
let's dont compile Qt but install it from trusty repo
Added conf for Qt 5.2.1 avaiable in Ubuntu Trusty
Merge pull request #2353 from Kakadu/master

conf for Qt 5.3.1 with source depexts