fix cause of PHP notices and some more pedantic stuff

This commit does not change the features of the installer nor does
it add any new features or introduces changes required for the
installer of alix6.
Its intention is just to make the code a bit cleaner.
better compression for PNG images
structure
abstract runner and sqlrunner
first concept for selfreloading pages

Signed-off-by: Sweil <mail@sweil.de>
phpinit
finished IncrementalRunner and IncrementalFSVersionRunner
concrete SQLRunner implementation

Signed-off-by: Sweil <mail@sweil.de>
Create README.md
Update README.md

konzept
fix typos in README.md and SQLRunner
Merge pull request #1 from Thoronador/generic-approach

fix typos in README.md
small fixes

Signed-off-by: Sweil <mail@sweil.de>
Merge remote-tracking branch 'remotes/origin/generic-approach' into generic-approach
added some libs from fs2
=> they can be removed when the installer is integrated into the fs2

Signed-off-by: Sweil <mail@sweil.de>
simple index.php

Signed-off-by: Sweil <mail@sweil.de>
some progress

Signed-off-by: Sweil <mail@sweil.de>
some progress

Signed-off-by: Sweil <mail@sweil.de>
checker class
sql connections checker
generic page class
start & database now based on page class

Signed-off-by: Sweil <mail@sweil.de>
finished class structure
Bug: result array from session

Signed-off-by: Sweil <mail@sweil.de>
little file organization clean up
(still have to delete old files)

Signed-off-by: Sweil <mail@sweil.de>
fixed result storage on selfreloading pages

Signed-off-by: Sweil <mail@sweil.de>
added requirements checker
some logical changes
file list can now handle none (so installer and updater are now totally the same, yay!)+

Signed-off-by: Sweil <mail@sweil.de>
started work on style

Signed-off-by: Sweil <mail@sweil.de>