Limit line-length to 79 characters

[ana]

In the moment of writing this issue, the master branch has 1044 lines longer than 79 characters.

This ticket is about removing all these long lines and then enabling the corresponding pylint check C0301 and max-line-length option in pylint as follows:

--- a/.pylintrc
+++ b/.pylintrc
@@ -81,7 +81,6 @@ disable=W0212,
   C0200,
   C0201,
   C0209,
-  C0301,
   C0302,
   C0321,
   C0325,
@@ -382,7 +381,7 @@ indent-after-paren=4
 indent-string='    '
 
 # Maximum number of characters on a single line.
-max-line-length=100
+max-line-length=79
 
 # Maximum number of lines in a module.
 max-module-lines=1000