Merge pull request #42 from racklin/master

phpbrew switch / use command should check targeted php version exists
Fixed phpbrew init generated bashrc not contains php version exists checking code.
Signed-off-by: Rack Lin <racklin@gmail.com>
Fixed +default+pgsql will not configure with pdo drivers issue, and added recursive and duplicate options check.

Signed-off-by: Rack Lin <racklin@gmail.com>
Merge pull request #45 from racklin/pdo_drivers

Fixed +default+pgsql will not configure with pdo drivers issue
Merge pull request #44 from racklin/switch_check

Fixed phpbrew init generated bashrc not contains php version exists chec...
bump version for bug fixes