Merge pull request #4 from petere/master

Fix build with PostgreSQL 9.3devel
v2.5
deb cleanup

* use installed pg_buildext
* use installed pgxs_debian_control.mk
* don't override 'clean' target in debian/rules
* 'make deb' forces control file regeneration

This reduces crap maintained locally.

It also does mean that to build against server-dev-X.Y package
that is not for Debians default Postgres version, following packages
need to be installed from PGDG (wiki.postgresql.org/wiki/Apt) repo:

  postgresql-client-common
  postgresql-common
  postgresql-server-dev-all
Add additional built files to .gitignore
Add more test cases for error conditions
Add language validator

Refactor some internals to make this possible.  Mainly, FunctionCallInfo
is not available when validating, so avoid accessing that if not
required.  Rename plproxy_compile() to plproxy_compile_and_cache() and
the previously internal fn_compile() to plproxy_compile().  This matches
their purpose better and allows the validator to call plproxy_compile()
without invoking execution-time dependent code.

Many error test cases have changed because the validator catches errors
when the function is created, not when it is called.

Raise the extension version to 2.5.1 to be able to upgrade from
non-validator installations.
remote_wait_for_cancel: wait only C_QUERY_READ connections.

Previous check was too broad and left plproxy hanging.

Reported-By: Tarvi Pillessaar
Comment typo
Instead 2.5.1, use 2.6 as next ver.

the validator is too big change for 2.5.1
remote_wait_for_cancel: move pending check before poll()

Otherwise it can still hang.
Use setseed() in RUN ON ANY regtest.

Without it, the test can fail occasionally.

Reported by Peter Eisentraut.
remote_wait_for_cancel: avoid unnecessary warning

If the remote server cannot be connected and query is canceled,
don't show random warning about "Unfinished connection".

Patch by Fazal Majid
Security check for validator function
Fix typo in validator security check
Merge pull request #9 from petere/patch-1

Fix typo in validator security check