This change permits to use up-to-date compilers, clang-tidy and
clang-format
It also refactor the tidy/format step to drop the binary selection from
scripts and perform it directly in travis
The code 'if [ -z ${something} ]; then ... fi' means "if
${something} is an empty string, yell at the command line
about 'binary operator expected' and ignore the body of the
if statement, if ${something} is not an empty string,
the condition is false so ignore the body of the if
statement" which clearly isn't what the author wanted. Fix
it by adding a few quotes around the offending ${something}.
* Move GCC to GCC 6 & GCC 7
* Move Clang to Clang 3.6 & Clang 4.0
* LINT moves from Clang 3.9 to Clang 4.0
* Move XCode 7.3 to 8.0
* Use more travis tricks to install compilers instead of adding complexity to our build script
* Clang format fixes on checked files (compat Cpp11 instead of Cpp03)
* Mingw GCC update from 4.8.4 to 5.3 (Ubuntu Xenial)
* Drop mingw cmake generated files and add them to gitignore
Seems the diff mode doesn't work well, PR are detected as working whereas in master it's shown it's problematic (and really problematic). Use same check everywhere
