fixed memory leak, added more tests
fixed memory leak
build: updated configure to current program version

needed to rerun ./bootstrap to tell configure about version 0.3.2
changed automake from version 1.12.6 to 1.13.1.
It changed some makefiles and added test-driver script.
tests: added tests for XlsFile

- Tests don't need to be linked to xlslib
- access xlslib through an interface class "workbook"
- refactoring in XlsFile
removed trailing spaces