Improve curl error reporting.

Check for false instead of empty curl response, to make it fall
through to the proper error message in case of an HTTP error.
Add information on which verb is used when an error occurs.
when chroot location exists, offer to remove it
No longer grant access to from the world to the MySQL account.

This is the safe default and sufficient now since only the domserver needs
to access the database. Those running MySQL on a different machine need to
change this default.
Round time difference down to second precision.
Recognize all defined auth schemes on password generation page.
Document how to use SSL and how to teach judgehosts about a self signed certificate.
Fix install-time creation of SQL directories.
Thanks Matt Steele for pointing out.
Do not fail on error in judgehost poll loop, but just keep retrying.

This restores the approximate behaviour from the pre-API days, where
a failure to connect to MySQL would not lead to a judgedaemon crash
but would be retried until it works again.

In this implementation we only ignore errors in the poll loop when
the judgehost is idle. This is the most common state for a judgehost
and will not make all judgehosts crash if you need to restart Apache
or MySQL.

If a judgehost encounters an error when using the API as part of the
judging process, it will still crash. This seems the safest option.
Restarting the judgehost after such a crash will probably resolve
this state.
Fix comment typo.
Don't try to install affiliation logos: these have been removed
in ecd19691f9.
php-geshi no longer needed.
Upgrade spyc to 0.5.1.
Add basic composer.json metadata file.

Do not use composer for dependency management just yet; our only
external lib is currently Spyc and the results are quite ugly.
Add config check for maximum upload filesize.
Add JavaScript language support (via node.js)
Note in ChangeLog that JavaScript has been added as a supported
language. Thanks Matt Steele.
Use unzip/zip instead of ZipArchive class.

The php ZipArchive class lacks support of setting executable bits.
Suggest to increase number of processes when the JVM runs in an OutOfMemory error.
Remove duplicate code to calculate bytes from php ini values.
Specify type of executable when uploading.