Remove line limit rule

As an alternative to https://github.com/invenia/BlueStyle/issues/59
while the whole guide is suggests, we could be more explict about the line limit being a suggestion.

What if we removed the line limit rule, and said instead something a long the lines of:

Lines should be kept to a reasonable length.
In general 92 characters is a reasonable length, but for some things longer (or shorter) may better promote clarity.
For example rather than very long list of function arguments on one line instead ....
or for ternary expressions use if instread, e.g. ...
Conversely, for log messages its often clearer to have a very long string than to split the string up and then concatenate it back together.

Argument for this over #59 is that if you are going to set up to need to deal with really long lines, and thus have your editor either setup to wrap or to horisontal scroll, then once you are setup to do it for string literals it remains setup for other needs.
Counter argument is that strign literals are infact special, and you often don't need to care what is at the other end of the string -- because its almost always a log message or similar, so you only look at enough to workout what it is telling the user.

Just putting this alternative out there for consideration

Read the alternative proposal in issue #59 and compare it with the current line-length guidance in the BlueStyle guide. The issue presents competing considerations rather than naming a file or test; done would require a maintainer decision about the wording and corresponding guide change.