Move up to Linaro 14.07 toolchain

Tests show a slight reduction in code size compared to 13.11.

User guide updated.

Fixes ARM-software/tf-issues#207

Change-Id: I9b80a5d7820cdfd443cac4d4b63f925b74a8c3a3
Merge pull request #180 from jcastillo-arm/jc/tf-issues/207

Move up to Linaro 14.07 toolchain