New "System Configuration" installation step

For In-Portal 5.2.0 we are proposing to add new System Configuration step to Installation process + Update System Configuration option for "Installation Maintenance" (to make changes after the installation). The purpose of this step would be to manage System Settings which can't be saved in the Database due to code architecture and must be accessible before connection to the database for better performance.

Below is description of how it can work.

[B]1. New Installation:[/B]

Add System Configuration step (after Basic Configuration step) and make this step to be visible ONLY when Debugger is ON.

It will list the following variable (all MUST be saved in system/config.php):

WebsitePath (string, default to current installation path)
WriteablePath (string, default "/system")
AdminDirectory (string, default "/admin")
AdminPresetsDirectory (string, default "/admin")
ApplicationClass (string)
ApplicationPath (string)
CacheHandler (drop-down with current options), auto-detect (try to check from more powerful to less powerful in following order: Memcache <- XCache <- APC)
MemcacheServers (string, default "localhost:11211")
CompressionEngine (drop-down with None, PHP-based, YUICompressor (Java), Auto-Detected by default)

[B]2. Installation Maintenance:[/B]

Add Update System Configuration option after Update License Information option.

WebsitePath (string, default to current installation path)
WriteablePath (string, default "/system")
AdminDirectory (string, default "/admin")
AdminPresetsDirectory (string, default "/admin")
ApplicationClass (string, visible with Debug ON)
ApplicationPath (string, visible with Debug ON)
CacheHandler (drop-down with current options)
MemcacheServers (string, default "localhost:11211")
CompressionEngine (drop-down with None, PHP-based, YUICompressor (Java), Auto-Detected by default)

NOTE: remove variable definition from config.php file, when entered value matches default one.

[B]Description (right hand side) for this new section can read something like this:[/B]

These are system advanced settings and must be changed with caution. It's not recommended to change these settings unless you know what you are doing. These settings will be stored in system/config.php file and can be changed manually if needed.