Add parsley:attrname() XPath extension to get an element's attributes names
Revert to smart_strings=True (for the time being), used for :attrname()
Adapt elements2textnl to accept replacement string
Fix __version__ name and increase version
Change namespace for local XPath extensions to "local-parslepy"
Add prefix "parslepy" for "local-parslepy"
Previous prefix "parsley" is kept as alias
End loop after first results for not iterating scoped extraction
Empty list becomes {} when not iterating
Add Parslet alias for Parselet class
Add test for parslepy:attrname()
Add alias 'attrnames' since the extension
returns a list of attribute names
Move built-in XPath extensions functions to funcs module
Add parslepy:xml() XPath extension
Rename parslepy:str/strnl to parslepy:text/textnl.
Keep previous as aliases
Fix paslepy:text() for Python 3
Set smart_strings=True only for parslepy:attrnames() and user extensions.

Instances of Parselet have their own extensions and namespaces attribute
(EXSLT_NAMESPACES and PARSLEY_XPATH_EXTENSIONS content was not copied
to instance but updated in place...)
Change PARSLEY_NAMESPACE to LOCAL_NAMESPACE
Merge branch 'master' into v0.2a1

Conflicts:
	parslepy/__init__.py