loose CMake minimum version requirement
clean Makefile.mingw a bit
travis-ci: install cmake from ubuntu repository
travis-ci: install and use gcc 4.7
travis-ci: install g++4.7 non interactively...
travis-ci: limit number of CPUs used during compilation
TAB: make "Stem through staves" option more similar to regular pitch layout.
Merge pull request #245 from mgavioli/TAB_stems_through_staves

TAB: Stems through staves option
travis-ci: fix multi cpus build
TAB: do not draw stem portions between notes.

Also stop the stem a little before reaching the first note.
Merge pull request #249 from mgavioli/TAB_no_stems_between_notes

TAB: No stems between notes
Time Signatures: on staves with an odd number of spaces, do not leave an empty space between numerator and denominator.
inspector tweaking
fix inspector geometry management
Merge pull request #250 from mgavioli/TimeSig_on_even_lined_staves

Time Signatures in staves with even number of lines
Fix 20405: in TAB's, small notes collide with staff lines.
Merge pull request #251 from mgavioli/Fix_20405_TAB_small_notes

Fix 20405: in TAB's, small notes collide with staff lines.
TAB: the length of beam partial segments was wrong (too long for down-stems and too short for up-stems)
add tuplet properties to inspector
Merge pull request #252 from mgavioli/TAB_lenght_of_beam_partial_segments

TAB: Lenght of beam partial segments