Add extra partition functionality.

[suikan4github]

Current Kaiten-yaki allows "bulk" partition for one OS. For example, It allows :

• /
• SWAP

So, it doesn't allow separated /home or /var. To be a better user operation, we should allow extra volume creation during the installation.

For example,

export LVROOTNAME=anko
export USELVEXTRA1=1
export LVEXTRA1SUFFIX="_home"
export USELVEXTR2=0
export LVEXTR2SUFFIX="_var"

In this case, the following LVs are created

• anko
• anko_home

In the overwrite mode, extra volume settings are just ignored. Existing volumes are untouched. And it should not be deleted in the cancelation.

In the non-overwrite mode, the extra volumes have to be created with specified volume size. And it should be deleted in the cancelation.

[suikan4github]

Merged to develop. ready to release.