improved handling of nil values. (Not 100% backward compatible.)

Note: this changes the output of erlsom:scan() in case there are nil elements (xsi:nil=true) in the input.
Remove duplicate call and a clause that cannot possibly match
Fix matching with return value of http_uri:parse/1 (R15) and a grammatical error
Comment out clause that is currently useless
Handle case where characters are binary

When using utf8 output_encoding, the old code would crash for a
CDATA which was not flush with its surrounding tags.
Deleted .beam file
Merge branch 'dialyzer-fixes' of git://github.com/kostis/erlsom into issue_11
More detailed error messages. Include the relevant tag name when throwing an invalid XML error.
Honour the 'include_dirs' option as mentioned in the documentation.

Also include 'dir_list' for backwards compatibility.
Consistently use 'include_dirs' in comments and documentation
Add the schema compilation of the GEXF XSD as a test.
Remove duplicates.
Delete duplicates of types.
Add tests.
ertlsom:write/2: use 1 whitespace as a delimeter only. Use short tags like <br/> when can.
Rewrite write_hrl function, add the support of erlang types inside a hrl file. Add comments inside a generated hrl-file.
Add stability tests.
erlsom_lib: https support
erlsom_write: Namespace order priority fix
Merge commit 'edescourtis/master' into merge_edescourtis

Conflicts:
	src/erlsom_compile.erl