replace tab-based indentation with some consistent space-based indentation

[erikdw]

A commonly adhered to coding style is to use a consistent number of spaces for indentation within code. e.g., 2 or 4 spaces.

However, it appears that much of the JStorm code uses tab characters instead. Using tabs has various issues. e.g.,

• the lines of code appear overly wide in browsers since they usually default to using 8 monowidth character positions to represent the tab character.
• issues with using diff and other UNIX command-line tools when you have a mixture of tab-based indentation with space-based indentation (which is inevitable)

Here are a few articles outlining various reasons to not use tabs:

• https://opensourcehacker.com/2012/05/13/never-use-hard-tabs/
• http://jarrodoverson.com/blog/spaces-vs-tabs/
• http://emacswiki.org/emacs/TabsAreEvil
• etc. etc.

[longdafeng]

We will fix this issue in 0.9.6.4