Add is_array_assoc() and array indexed and associative tests
Fix #4: Arrays inside the data array loses its indexes
Merge branch 'master' of https://github.com/php-curl-class/php-curl-class into php-curl-class-master

Conflicts:
	Curl.class.php
Fixes issue #6 "Integer params inside data array aren't taken in account"

Makes the http_build_multi_query method to be also able to add integers inside the data array

Signed-off-by: Dani Sancas <dani@sancas.es>