updated todo list
added new template class
added new subpage class
renamed subpage module
made imports relative
created test case for 'template'
added __init__.py
clearer name for exception
added test for subpages
fixed typos that prevented test from running
minor code rearrangements
created warning system
rename warnings module
got rid of redundant 'HtmlSubpage' class
greatly simplified that useless warning system
added tests for webpage generation
implemented webpage generation
updated todo list