[NaCl SDK] Seperate LIBS and DEPS in .dsc files.

Previously anything in DEPS was implicitly added to LIBS.
This makes precise ordering of LIBS difficult.  Now we can
have DEPS that are not necessarily included in LIBS.

Also, explicitly exclude ppapi_simple when in SEL_LDR
builds. Right now this feature is a hard-coded into
parse_dsc.  This change is required before I can commit
the change to  ppapi_simple to allow the use of the 'main'
entry point: https://codereview.chromium.org/16626007/

R=binji@chromium.org, noelallen@chromium.org

Review URL: https://codereview.chromium.org/23902043

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@249511 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 249511