SPARK-1965: Replace emoticon archives with separate files in version control
Instead of adding the zip files to git, this commit adds the unzipped content, and ensures that the Maven build generates the zip files. This way, editing is a lot easier, and changes are better tracked.
SPARK-1962: Don't force smilies to lowercase.
The old code was doing "smiley-text to image" lookup by converting everything to lowercase, then doing a
case insensitive lookup. My last commit made that lookup case sensitive, which caused lookups for :-D and :-P to fail.
This commit remove the to-lowercase conversion of the text that's used in the lookup, fixing those instances again.
