Modified: Change tab from hard to soft (4 spaces)

[futoase]

improve indent of include files.

change tab from hard to soft (4 spaces).

[muojp]

Thanks for your contribution. We're sorry but we could not merge this pull-request this time.

Reasons:

• We recognize it's important and it is not unified in current tree.
• Hard-tabs vs soft-tabs is not a tiny change. it could effect every code written on this project.
• So we need to discuss and determine code styling prior to start making actual changes.

Instead of merging, we'll welcome you to join us discussing code styling. We're planning to apply automatic code formatter once prepared (because we need to sync our in-company tree and OSS version smoothly). #32 would be the nice place to have further discussion.

[futoase]

We're planning to apply automatic code formatter once prepared
#32 would be the nice place to have further discussion.

I understand.