Apply Lei Zhang's patch to add easy import of additional environment...

Apply Lei Zhang's patch to add easy import of additional environment
variables in our scons setup.

Here is an example of importing an additional environment variable:

export MYVAR='value'
scons importenv="MYVAR"


Committed: http://code.google.com/p/v8/source/detail?r=1671

[Kevin Millikin (Chromium), 2009-04-02 12:54:10]

It seems plausible.  LGTM.

http://codereview.chromium.org/60046/diff/1/2
File SConstruct (right):

http://codereview.chromium.org/60046/diff/1/2#newcode511
Line 511: result.Add('importenv', 'import environment settings (NAME1,NAME2)',
'')
Might be clearer to have the message string:

'import environment settings (NAME1,NAME2,...)'

Also, consider zero-based indexing.  :)

http://codereview.chromium.org/60046/diff/1/2#newcode632
Line 632: # The environment imports are in the format NAME1,NAME2
Analogously here.