DESCRIPTION/LICENSE meet CRAN reqs
updated examples in entrez_fetch

As per issue #10, these changes make exmaples keep track
with changes to the code. Have also removed "dontrun" from
several examples so these issues should be tested at
R CMD check time
Fixed bug in entrez summary

Previous to this commite, the esummary parser was parsing _entire files_
for each subrecord requests with multiple IDS. This led to very large
esummary objects that could not be properly mapped to record IDs
added print method for multi-record esummary results
updated README and added tests to reflect changes in last commit
build new docs
Merge branch 'master' of github.com:ropensci/rentrez