Revert pull request #295 (xhr-headers)

breaks existing installations
Fixed #292 (pulldowns loose lines when exported as library)
Fixed #291 (readonly custom menus become non-readonly when block is edited)
Translate new stop commands.
Fixes issue #310 - play note block fails on Firefox due to use of deprecated
WebAudio names. The fix uses the correct names and monkey-patches browsers that
use the old ones.
Update lang-fr.js

add the french translation of the block "pause all"
Fixed #313

“Block OF sprite” now works for interpolated (“timed”) blocks and for
reporters (i.e. SAY FOR, THINK FOR, GLIDE, ASK etc.)
Morphic: Replaced deprecated DOM “body” references with “documentElement”
Import costumes and backgrounds from the project menu

thanks, Brian, for the changeset!
Import sounds from the project menu

Thanks, Brian, for the changeset!
Flat line end option in the settings menu, saved with the project
German translation update
Merge pull request #311 from brettle/master

Fixes issue #310 - play note block fails on Firefox
integrate Dean's sound fix

so JSLint doesn’t complain (no functionality changes). Thanks, Dean!
Merge pull request #305 from MMSequeira/master

Translate new stop commands.
Merge pull request #312 from gego51/patch-2

Update lang-fr.js
Integrate Portuguese and French translation updates
One-stop-shopping for stage dimensions

changing the stage dimensions in line 3720 of objects.js takes care of
everything