COMP: Google double-conversion (reduced)

This corresponds to commit hash
  c7734598e2ee084c17e1b8a41daa569fb021d593
from Google repository
  http://code.google.com/p/double-conversion
COMP: Merge of double-conversion upstream changes

This incorporates the upstream changes by Google
to the double-conversion library as of April 25, 2014.

The google repository
https://code.google.com/p/double-conversion hash is
c7734598e2ee084c17e1b8a41daa569fb021d593

Primary upstream changes were fixes for compiler warnings
and support for non-intel platforms.

Some cmake and SConstruct build system fixes.

Merge branch 'DoubleConversion-upstream' into DoubleConversion-update

Change-Id: Ia7cd2095cc861f95d8e3f70a6864a4a34bffaac3
COMP: Update the DoubleConversion library upstream update script.

1. Replace the SHA for DoubleConversion-upstream
2. Fix the commit message for DoubleConversion-upstream

Change-Id: I77d57a25fd1fe2dad41167dad3773ad72e77ffbf
Merge topic 'DoubleConversion-update-Script-Fix'

9493a13e COMP: Update the DoubleConversion library upstream update script.
bc36510f COMP: Merge of double-conversion upstream changes
1feae55e COMP: Google double-conversion (reduced)