add .sass-cache directory into the default .gitignore file
add .idea which is RubyMine project directory into the default .gitignore file
fix a bug in detecting dependencies where it would cause build error when passed non-flat array into `app.files'
Speed up build a little bit.

We use rubymotion v1.30 with new automatically detected file dependencies. We have very slow builds (about 30 secs on not cold builds) in project with only 52 ruby files.
After investigating I found that almost all build time rubymotion spend in `Motion::Project::Config#ordered_build_files` (about 24 secs).
`Array#uniq` does exactly what `orderd_build_files` is doing but much much faster.
With this change `Motion::Project::Config#ordered_build_files` takes only about 0.06 secs on my machine.
Merge pull request #63 from anjlab/speed_up_build

Speed up build a little bit.
fix a bug in `rake spec' which it would raise an ArgumentError when use "it" without block

A following spec will raise an ArgumentError.

	describe "Application 'test'" do
	  it "has one window"
	end

`instance_eval' will pass a receiver object into block.
When use a block which created by lambda, it should accept a receiver object as block parameter.

	b = lambda { self.upcase }
	"test".instance_eval(&b) #=> wrong number of arguments (1 for 0) (ArgumentError)
fix a tap format in `rake spec' to output the each test numbers instead of the total number

## before
$ rake spec output=tap
ok 34  - works with Assets
ok 34  - works with hash
…
ok 34  - should work
1..34
# 34 tests, 61 assertions, 0 failures, 0 errors

## after
$ rake spec output=tap
ok 1   - works with Assets
ok 2   - works with hash
…
ok 34  - should work
1..34
# 34 tests, 61 assertions, 0 failures, 0 errors
add a message of `describe' to description of tap's output

## before
not ok 1 - has one window: FAILED

## after
not ok 1 - Application 'test' has one window: FAILED
remove a `#' if it is included in first character in tap's description because its description will handled as comment in tap format
add app/pixate_code.rb into the default .gitignore file because it contains the Pixate license key
1.31
1.32
slightly delay the start of spec execution

Because #tap method does not work when use a high performance machine
convert a string encoding which retrieved from filesystem

The OSX filesystem uses UTF8-MAC as file name encoding.
Its encoding has a character that does not match UTF-8 encoding.
(ex, "が" in Japanese)