Direct Rendering Infrastructure fixes for DMTCP

git-svn-id: svn://svn.code.sf.net/p/dmtcp/code/trunk@2221 ba6dc0ae-232f-0410-883f-9ebac64fc565
SysVSHM: Find out correct size if user passes 0.

git-svn-id: svn://svn.code.sf.net/p/dmtcp/code/trunk@2222 ba6dc0ae-232f-0410-883f-9ebac64fc565
SysVSHM: Refresh _realId on restart.

git-svn-id: svn://svn.code.sf.net/p/dmtcp/code/trunk@2223 ba6dc0ae-232f-0410-883f-9ebac64fc565
CoordAPI: Do not send ckptfilename during restart.

git-svn-id: svn://svn.code.sf.net/p/dmtcp/code/trunk@2224 ba6dc0ae-232f-0410-883f-9ebac64fc565
Call mtcp_init() without ckpt filename.

git-svn-id: svn://svn.code.sf.net/p/dmtcp/code/trunk@2225 ba6dc0ae-232f-0410-883f-9ebac64fc565
Minor re-org of UniquePid.

git-svn-id: svn://svn.code.sf.net/p/dmtcp/code/trunk@2226 ba6dc0ae-232f-0410-883f-9ebac64fc565
Create ckpt dir only after threads have suspended.

git-svn-id: svn://svn.code.sf.net/p/dmtcp/code/trunk@2227 ba6dc0ae-232f-0410-883f-9ebac64fc565
Fix for unique checkpoint filenames.

git-svn-id: svn://svn.code.sf.net/p/dmtcp/code/trunk@2228 ba6dc0ae-232f-0410-883f-9ebac64fc565