add posibility to use 'autopart' or 'part' in redhat's kickstart

'autopart' (an option in redhat's kickstart) is cool, but if my disk has 2T of space, after installation there will be 50G of root partition and 1.5T of /home, and it's not what i want.

```
# df -h
Filesystem                         Size  Used Avail Use% Mounted on
/dev/mapper/vg_autopart1-lv_root   50G  775M   46G   2% /
/dev/mapper/vg_autopart1-lv_home  1.6T  197M  1.5T   1% /home
```
                                             
Changes allow to manually set size of root and swap partition or to use autopart (default).

We can create two(or more) models with different partitions, based on red hat template, eg:
- for phisical servers
     * 16G / 
     * 8G swap
- for virtual servers 
     * 4G /
     * no swap