updating clojure & poi
fix: missing cell style
improved doc
choice: xssf or hssf model

fixme: quick impl; duplicate code
'save' should close the stream instead of returning it.
first test
making the test pass

* loading of sheet names (hssf)
* use 'cell-value' directly
another test: roundtrip different value types
be more ignorant
modified set-cell behaviour; initial style support; other fixes
CI test build
fix doc; added travis-ci link
css border order fix & testcase
fix amusing copy & paste error
Enable automatic style handling in build-workbook; remove old style code.

For map-typed cell values styles are build from css-like attributes; the
impl is neither efficient nor elegant - but it should reuse identical styles.
cell styles: test, some fixes & documentation
Merge pull request #1 from undernorthernsky/master

Major updates and cleanups to clj-excel.