Adds a new 'debug' target, just for convenience.
Command libcheck not fork() on each test. It makes debugging weary.
Adds a new QA entry to cover chula_buffer_get_utf8_len().
It's safer to check for emptiness using chula_buffer_is_empty()
Adds another QA entry to cover chula_buffer_unescape_uri().
Clean-up around the internal escape_with_table() function.
Adds a new QA test for the chula_buffer_escape_uri() function.
Adds a new QA test to cover chula_buffer_escape_uri_delims()
Adds a new QA bench entry to test chula_buffer_escape_arg()
The '/' should be escaped as well.

According to the 'ESAPI reference implementation', the '/' char has to
be escaped in HTML as well.
Adds a new QA entry to cover chula_buffer_add_escape_html()
The base64 functions did not handle empty buffers properly.
Adds QA for base64 functions

Adds a new test to cover the base64 related functions:
chula_buffer_encode_base64() and chula_buffer_decode_base64()
Adds a new QA test to cover chula_buffer_encode_md5_digest()