x264 iOS build script

See https://github.com/kewlbear/FFmpeg-iOS for integration with FFmpeg and more.

This is a shell script to build x264 for iOS apps.

Tested with:

Usage

Untar the source code into a folder named x264
To build everything:
```
  ./build-x264.sh
```
To build for arm64:
```
  ./build-x264.sh arm64
```
To build fat library for armv7 and x86_64 (64-bit simulator):
```
  ./build-x264.sh armv7 x86_64
```
To build fat library from separately built thin libraries:
```
  ./build-x264.sh lipo
```
Library and Header Files are in ./x264-iOS