Fixed `fish-shell` support bugs, and removed unnecessary hash commands.

Signed-off-by: Rack Lin <racklin@gmail.com>
Fixed search for apxs2 binary
Merge pull request #426 from racklin/bugfix/fish-shell1

Fixed `fish-shell` support bugs, and removed unnecessary hash commands.
Some comments and extra debug info
Merge pull request #427 from morozov/apxs

Fixed search for apxs2 binary
Runs make clean before installing an extension.
Merge pull request #425 from shinnya/feature/extension/make_clean

Runs make clean before installing an extension.
Using tr command to instead of bourne shell IFS function. fixes #431

Signed-off-by: Rack Lin <racklin@gmail.com>
Merge pull request #432 from racklin/bugfix/431

Using tr command to instead of bourne shell IFS function.
Uses environment variables defined in phpunit.xml in ConfigTest.