add ios-sim source code, so it can be leveraged
Copied over the ios-sim built using
	rake install prefix=/usr/local/
from
	build/Release/ios-sim
and placed it in
	native/ios-sim

I chose the ios-sim https://github.com/phonegap/ios-sim
because it seems that its the latest at the moment for
Xcode 6 support.
Removed ios-sim-old because it is not used.  I recently overwrote
the ios-sim with a newer one (version 3).
ignore gem files that have been built
Update version number to reflect the newer ios-sim being used
README with note on binary ios-sim added
Binary ios-sim removed
Mention binary dependency in a post install message
Merge pull request #1 from crishoj/topic/ios8-support

Get rid of binary `ios-sim`
Merge pull request #33 from faisalmemon/topic/ios8-support

Topic/ios8 support
bump version to 0.5.0, since removing the ios-sim binary is a breaking change
force tall & retina