remove woff fonts to

save space in the package as well as generated documents
update telex font
Revert "update telex font"

This reverts commit a57d8d9fc79fd92494879e292b665b44e9b51abc.
update opensans fonts
Revert "update opensans fonts"

This reverts commit 88f8d5d5749eff789db290071194484b1040ed95.
fix links to contributor agreements
Switched to titling package and maketitle for latex
Updated titling formatting to allow for missing components
Merge pull request #252 from robjhyndman/master

Switched to titling package and maketitle for latex
remove revealjs format
expose includes_to_pandoc_args function
expose relative_to function
document filter parameter
Merge branch 'feature/remove-revealjs'
custom error message for unqualified references to revealjs presentations
remove embedded mathjax