Task::Auto loading without scanning file system

Previously framework is loaded by scanning file system and adding files
avaialble to autoloading.
After that we introduced filetree concept, in that we used to generate
all files list on cron. It helps to avoid filesystem scans. But
generating filetree was complex and depends on cron.

Now we will generate filelist at the time of building rbframework zip.
This will reduced the code and also speedup the framework autoloading.

Loading time on ubuntu 14.04, PHP 5.5, Core i7 4800MQ + 16GB Ram, have
been slashed from 2.1 ms to 0.4 ms.

To facilitate above filelist based autoloading, few changes were require
e.g. adapt folder code have 2 clases with same name in different file,
so autoloading was conflicting. This have been rectified by ensuring
that one class is only available in one file.

Impact : rb_import, which auto-loads pkg folder is not required.

Fix #52 Test #52