Fix temporary folder name generation collisions

First, the regular expression matches everything after the first period
in a filename.  Adding the $ make it match the last, so that filenames
such as “Report.1.pdf” get trimmed to “Report.1”.

Next use mktemp to get the OS to create a temporary folder.  It will
guarantee a unique directory name beginning with prefix, even if parallel
processes are at work.
Fix AttributeError on self.width if Tesseract finds no OCR text

self.width remains undefined unless hOCR finds text.  It might not, if
a page contains only an image for example.

Full error message is:
AttributeError: ‘hocrTransform’ object has no attribute ‘width’
Verify that pdftoppm is the Poppler version, not xpdf version
Merge pull request #55 from jbarlow83/for-upstream/check-poppler

Verify that pdftoppm is the Poppler version, not xpdf version
Merge pull request #56 from jbarlow83/for-upstream/hocr-selfwidth

Fix AttributeError on self.width if Tesseract finds no OCR text
indicate python2 to be used in header
minor changes
Merge pull request #57 from jbarlow83/for-upstream/tmpfolder

Fix temporary folder name generation collisions
Check of tmp folder creation was successful
config file restructured

to be make which parameters are allowed to be changed by the user
better handling of ligatures: fixes #58
Use --gnu in parralell and XX for mktemp

Signed-off-by: Mansour Behabadi <mansour@oxplot.com>
Make src scripts executable

Signed-off-by: Mansour Behabadi <mansour@oxplot.com>
Readme improved
merged pull request from oxplot
tmpfiles to $TMPDIR + better portability (mktemp)

mktemp: consider both FreeBSD/OSX and Linux OS having incompatible
syntax
From now on temporary files are saved in the folder specified by the
environment variable $TMPDIR
disclaimer added
portability improvements + minor changes
dependency to pdftk removed

concatenation is now done also with ghostscript
wording corrected