Update "themeinfo" for Moodle 2.6 to use core_useragent.

Error message: "get_device_cfg_var_name" and "get_device_type_list" have been deprecated, please update your code to use core_useragent instead.

Copy the ThemeInfo command to the 2.6 commands, change the namespace "Moosh\Command\Moodle26\Theme" and implement the \core_useragent calls.
Update "includes/function.php". Replace deprecated "context_instance_preload_sql", add "f.id" to the fields in the query in get_files.

Add "f.id" to the fields in the query in get_files because "f.contenthash" could return identical entries.
Merge branch 'master' of git://github.com/uhunkler/moosh into uhunkler-master

Conflicts:
	includes/functions.php
Merge branch 'uhunkler-master'