Rlease GCC ARM Embedded 4.7 update 4

Written for GNU Arm Embedded Toolchain by Terry Guo on 2014-04-29

4.7 2014q2 (update 4) is released at https://launchpad.net/gcc-arm-embedded/4.7/4.7-2014-q2-update.

Important bugs fixed in 4.7 update 2014q2 release:
* Fix ARM NAN fraction bits
  https://sourceware.org/ml/libc-alpha/2014-02/msg00740.html
* Incorrect code when aligned access to volatile packed struct
  https://bugs.launchpad.net/gcc-arm-embedded/+bug/1197604
* ICE reload1.c:1058 using 4.8 with mthumb fomit-frame-pointer
  https://bugs.launchpad.net/gcc-arm-embedded/+bug/1278004

Recommend to upgrade your 4.7 tool chain to this release.