- Force Hide Tooltip of the pixel inspector when the tool get disable.
- take over Qt for greying icons by providing a disable version of each icons that need one.
Merge pull request #428 from est77/master

Fixed object space PR comments.
Merge pull request #429 from fewo/master

Pixel inspector tooltip hiding / add new icons.
immediately show the pixel inspector when 'i' is pressed.

tweaked the text of the pixel inspector tooltip and refactored the code.
using spaces instead of zeroes to pad pixel coordinates in the info label.
tweaked tooltip text.
many improvements around the project file watcher functionality.

- the Toggle File Watcher toolbar button and corresponding menu items are now checkable.
- moved the corresponding menu item to the File menu.
Split spectral input formats into spectrum only and spectrum+alpha
Merge pull request #383 from ixartz/master

Split spectral input formats into spectrum only and spectrum+alpha. Issue #344.
documented the usage of PRINTF_FMT and PRINTF_FMT_ATTR().
cosmetics.
added an assertion.
added an assertion to clear a potential bug reported by static analysis.
changed Importance Multiplier and Light Near Start input types from text to numeric.
Added guard against git_tag variable retrieval when building within
a non-git repository e.g. a tarball of the Appleseed source archive
Merge pull request #432 from nyue/master

Added guard against git_tag variable for non-git source tree tarball
fixed typos and formatting.
Fixed broken OSL build.