added per-user cache for mx downloads
made sha1 signatures mandatory for libraries; made libraries for all downloading performed by commands in mx_graal
modify the 'mx vm' command to check that the VM is up-to-date with respect to graalRuntime.inline.hpp
rename IntegerBelowThanNode to IntegerBelowNode

--HG--
rename : graal/com.oracle.graal.nodes/src/com/oracle/graal/nodes/calc/IntegerBelowThanNode.java => graal/com.oracle.graal.nodes/src/com/oracle/graal/nodes/calc/IntegerBelowNode.java
remove unused setters from BinaryOpLogicNode
small fix in FloatingReadPhase (when handling existing phis)
cached MatchPattern.Result failure constants
generalized check that VM is up-to-date with all generated sources
correct name of zero usages method
make scheduling before dumping optional to speed up dumping
Don't create useless ValueAnchorNode
Do final round of incremental conditional elimination