This commit fixes the following warning:
DeprecationWarning: 'U' mode is deprecated
Removing 'U' has no effect with Python 3 [1]:
There is an additional mode character permitted, 'U', which no
longer has any effect, and is considered deprecated. It previously
enabled universal newlines in text mode, which became the default
behaviour in Python 3.0.
[1] https://docs.python.org/3/library/functions.html?highlight=open#open
The change is only relevant to development as all the call to python scripts is done
calling C++ os::python that invoques the appropriate python version.
The change is two fold, on one hand remove all the uses of /usr/bin/env for python.
On the other hand rename all the calls to python from python to python3 making it explicit
and being compliant with PEP 394 -- The "python" Command on Unix-Like Systems:
https://www.python.org/dev/peps/pep-0394/
Remove the sheebang from src/graphics/GraphicsConverter.cpp because it is not necessary.
Some small whitespace changes.
'cat.py' created by Richard Heck
This script resembles the unix command 'cat', valid now on every
platform.
git-svn-id: svn://svn.lyx.org/lyx/lyx-devel/trunk@34828 a592a061-630c-0410-9148-cb99ea01b6c8
