`if` is for getting a value, not nec. side-effecty

Since `if` is more of an expression (rather than executed for side-effects), removed the "do-".

Since `when` supplies an implicit `do`, left the "do-", but removed the "else" (given the implicit `do`).
Merge pull request #26 from uvtc/patch-3

`if` is for getting a value, not nec. side-effecty
refined the rules about spacing around brackets of any sort
added a couple of comment style rules
Fix #21 - Remove "Use underscore in filenames..."
Added a few more namespace guidelines.
better formatting/indentation of example

Makes it more clear exactly what the threading macros are getting you.
Merge pull request #30 from uvtc/patch-4

better formatting/indentation of example
Elaborate on literal syntax for sets usage.
Merge pull request #32 from sw1nn/master

Set literal syntax only when values are compile time constants
Add a couple of rules for exceptions.
Discourage the use of Java collections and arrays.
Merge branch 'master' into zh_CN

Conflicts:
	README.md