updated czech translation

updated all strings based on sprint 25. also translated hardcoded strings.
fixed extensions

fixed extensions translation
handle the case where the CodeHintManager rejects a deferred hint
Update strings.js
modified:   src/extensions/default/JavaScriptCodeHints/ScopeManager.js
Don't update the modified range when 'null' keys (ctrl-space) are hinted.

modified:   src/extensions/default/JavaScriptCodeHints/main.js
When changing files, reset documentChanges to null.

modified:   src/extensions/default/JavaScriptCodeHints/unittests.js
Restore that content of a file after each test.
Update a test to wait for hints after it asks for hints. If the hints are not waited for the editor will be torn down before the hint completes, causing a null pointer exception.
Merge pull request #4080 from dloverin/fix-ctrl-space2

Don't mark document as modified when ctrl-space is pressed
Merge pull request #3927 from dloverin/handle-rejected-hints

handle the case where the CodeHintManager rejects a deferred hint
Merge pull request #3979 from kvarel/patch-2

updated czech translation