Use exec_dirs for rootwrap commands

Avoid depending on platform specific paths for rootwrap
by using exec_dirs in rootwrap. Fixes rootwrap configuration
for SUSE.

Fixes bug #1156044

Change-Id: I54d082c543fd84b40db0caa3571300ac0bb07b57
Add sqlalchemy_pool_size option to default config files

This patch exposes the sqlalchemy_pool_size option to config files of
plugins that already expose sql_ options besides sql_connection.

Fixes bug 1185260

Change-Id: Ifaff02fae5e5349efb992c071adc0b02f10d61a7
Merge "Use exec_dirs for rootwrap commands"
Merge "Add sqlalchemy_pool_size option to default config files"