Enable spell checking (#563)

* add spellchecking

* improve spelling

* improve spelling config

* extend word list

* improve spelling

* improve spelling

* escalate warning in spell check to failure

* fix spelling

* fix spelling

* add plural

* Update doc/spelling_wordlist.txt

* do not stop on warning

* require newest sphinxcontrib spelling

* remove old comment

* add authors as single line entry to spelling list

* reenable stop on warning

doc/spelling_wordlist.txt

@@ -1,7 +1,125 @@
-Raspbian
 ESC
+Esc
 POS
+Pos
 Escpos
 Escpos
+escpos
+
+bitImageColumn
+bitImageRaster
+ep
+pc
+cp
+
+csoft
+Frédéric
+Headcrash
+Krispy
+primax
+Tahri
+reck
+mrwunderbar
+zouppen
+kedare
+Foaly
+brendanhowell
+der
+fvdsn
+Marull
+Paretas
+Kakistocrat
+Billington
+patkan
+Romain
+Bougakov
+Yaisel
+Hurtado
+Wagenbach
+Poca
+Akram
+Vieira
+Christoph
+Heuel
+Thijs
+Triemstra
+Linder
+Romain
+Pulgarin
+Romain
+Cheng
+Dmytro
+Katyukha
+Elsdörfer
+Asuki
+Kono
+López
+mashedkeyboard
+Thijs
+Triemstra
+Elsdörfer
+Renato
+Lorenzi
+Bookham
+Goglin
+Christoph
+Heuel
+Qian
+Lehtonen
+
+barcode
+barcodes
 baudrate
-lsusb
+Bashlinux
+capabilities
+cashdraw
+charcode
+changelog
+cheque
+codebase
+codecov
+codepages
+config
+del
+dev
+dialout
+docstrings
+ean
+Ean
+encodable
+fff
+io
+json
+latin
+libusb
+lp
+lsusb
+natively
+php
+pre
+prefilled
+printcap
+programmatically
+py
+pypy
+pyyaml
+px
+qrcode
+Raspbian
+rebase
+rebased
+resetted
+rst
+submodule
+submodules
+src
+testcases
+th
+Todo
+traceback
+udev
+usb
+usec
+virtualenvs
+whitespaces
+xml