Fixed history and header update in IE

Due to Internet Explorer caching GET requests the Undo/Redo list and
column headers were not updated, leaving essential parts of the user
interface crippled even if Google Frame is installed. Adding
Cache-Control headers to the responses fixes this.
Fixed removal of upload temp files

Fixed an issue with an unclosed stream preventing upload temp files from
being removed after use. Also removed the use of FileCleaningTracker and
instead added manual removal of all tempfiles. By doing this the reaper
threads in FileCleaningTracker are avoided and files are removed
directly after use.
Updated logos with new ones - part of #630 rebranding
Merge pull request #668 from sparkica/new_logos

Updated logos with new ones - part of #630 rebranding
Tooltip is updated after changing facet expression - fixed #649
Merge pull request #669 from sparkica/fix_facet_tooltip

Tooltip is updated after changing facet expression - fixed #649
Merge pull request #665 from Arcadelia/IE_Cache-fixes

Fixed history and header update in IE by setting "Cache-Control", "no-cache" in HTTP headers
Added Java 8 to version check
Implementing Xor operation
indentation change
Update main/src/com/google/refine/expr/functions/booleans/Xor.java
Merge pull request #673 from jmcastagnetto/master

Fix for issue #671 and implementation
Merge pull request #666 from Arcadelia/Temp-file_removal

Fixed removal of upload temp files
Merge remote-tracking branch 'upstream/master'