added extract functions for extracting from pdfs
updated date and description of pkg in desc file
importfrom now from crossref the fxns needed in ft_providers
added tm fxns needed for extraction that were not exported
added pdfx fxn that parses a pdf to xml format from web
changes to some doc file
renamed extract fxns to have ft_ prefix, removed dplyr from imports
changed extract file names
changed travis file to try to install rcampdf from the non cran source
fixed up examples in extract man files
added note to fulltext to install rcampdf
Merge pull request #15 from ropensci/extract

pushing extract into master