adopt to Xcode 5.0.2

Use /Xcode.app/Contents/Developer/usr/bin/gcc to build
instead of iPhoneOS.platform/Developer/usr/bin/gcc,
since the later is absent in iOS 7 SDK.
Merge branch 'develop' of https://github.com/sakisakira/mobiruby-ios into develop
Make enabled of mruby-eval
Avoid crash in iOS 7 simulator.

Before the submit, the method runScript runs before @console_view is prepared.
So, I move the corresponding  process into viewDidAppear.
Merge pull request #45 from sakisakira/develop

adopt to Xcode 5.0.2 with iOS 7 simulator