Commited changes to allow a client to automatically refresh stale schema during certain ops.

[Sanjit Jhala]

Commited changes to allow a client to automatically refresh stale schema during 
certain ops.

-Allows clients to be transparently deal with non-conflicting schema changes 
during table mutations and certain hql commands

-Refresh cached schema on a client get_schema call
-Added regression test for changes

http://github.com/sjhalaz/hypertable/commit/45219966f231658755441cd58a74f0f4d844ae4f

-Sanjit

[Luke]

I suggest that we set a small refresh limit instead of using
while(true), to avoid accidental ddos on hyperspace.

[Sanjit Jhala]

-Allows clients to be transparently deal with non-conflicting schema changes
during table mutations and certain hql commands
-Refresh cached schema on a client get_schema call
-Added regression test for changes

http://github.com/sjhalaz/hypertable/commit/86dcd78076037f6d0c946ea882e7ab957755cc02

-Sanjit

[Luke]

HT_THROW2 should be used (see the note for line 380) to preserve the
exception chain.

[Sanjit Jhala]

Amended commit:
http://github.com/sjhalaz/hypertable/commit/956c66e113734bea23b194f9b81c742940bce9de