Initial mvvm-cross implementation

Restored the ignore (+2 squashed commits)
Squashed commits:
[d062787] Removed files added by mistake!
[5e33573] remove components from git (+2 squashed commits)
Squashed commits:
[68e85b9] add gitignore to ignore compoenents
[5139ad5] Add xamarin cross mvvm based implementation
Ensure prices are formatted in pounds
Moved solution into root folder
Added read me
Added generation of mvvm-cross assets
Added code sharing metrics for Xamarin-MvvmCross

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xamarin
---
{ common: 1916, ios: 1023, android: 1244, windowsphone: 1059 }
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xamarin-Mvvmcross
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{ common: 2079, ios: 516, android: 735, windowsphone: 336 }
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Merge branch 'mvvm-cross'

Conflicts:
	build/generate-assets.js
	build/stats.js