Introduced ClusterManager. Externalized support for new cluster types.
Improved error message for parseint on BigInts.
moved addprocs_scyld and addprocs_sge to deprecated.jl
Merge pull request #3649 from amitmurthy/amitm/cluster

Introduced ClusterManager. Externalized support for new cluster types.
Fix #3658
Don't insist that handles be valid in _get_osfhandle
package windows distribution as a self-extracting 7z file, since this results in 3x better compressesion
Fixes slow addprocs introduced by commit 17b3986
Merge pull request #3662 from amitmurthy/amitm/clusterfix

Fixes slow addprocs introduced by commit 17b3986
remove gc roots for variables that aren't used at all
WINDOWS: more useful "Please submit a bug report handler..." message