(#2437) Prepare tests that illustrate the issue

This patch takes the 3 examples provided in the issue description and
ensure that they fail when needed. It will help fixing the issue.
(#2437) Fix the first invocation of the class having bad parameters types

The first type we use Nagios::Base with a particular type, the method for
the parameters assignemtn are not present yet ; and it creates a side-
effect of changing the type of the parameters to Array.
It did break the rspec tests.
(#2437) Complete the tests to detect a variety of edge cases
(#2437) Escape semicolon (;) when writing Nagios configuration files

In nagios configuration files, semicolon (;) indicates a comment, except
when it is escaped with a backslash (\).
If we output a value with an unescaped semicolon, it will be considered
as a comment by Nagios, also by Nagios::Parser and thus the part
after the semicolon, included, will be lost.
Escaping the semicolon ensures it will be taken into account by
both Nagios and Nagios::Parser.
Cf http://nagios.sourceforge.net/docs/3_0/objectdefinitions.html
Cf xodtemplate.c in Nagios sources
(#2437) Fix the parser : comments, semicolon, ...

Lots of tightly coupled things here :
- The rules were modified to take care of an existing issue
that prevented to have full line comments (Starts with #) or
carriage returns just after a curly brace definition.
- The lexer was modified to consider an inline comment only
when a semicolon is not preceded by a backslash.
When a semicolon IS preceded by a backslash, it is considered
as escaped and is preserved (the escaping backslash is removed)
- The lexer was modified to allow pound (#) at every position
in a line (except the first character, which denotes a full
line comment)

Cf xodtemplate.c in Nagios source
(#2437) Compile the parser to ruby code

Parser is compiled with racc-1.4.9 while it was previously
compiled with racc-1.4.5 ; this causes a lot of cosmetic
changes and diffs.
(#2437) Comments can start with a pound (#) anywhere on an empty line

Nagios allows comments to start with a pound (#) anywhere on the line
if there are only spaces and/or tabs before.
This commit adds a test case for this, and fixes the parser accordingly.
(#2437) Prefer StringScanner in lexer (performance)

The lexer was previously doing multiple string manipulations.
My previous commits fixed the lexer, but introduced a 6x time
penalty compared to the original lexer, which was hard to remove.
Using StringScanner instead of strings substitutions is even
faster than the original lexer.
(#2437) Parser now using StringScanner in lexer (performance)
(#2437) Cosmetic changes for the tests
(#2437) Regex compatibility with Ruby 1.8.x

In the previous commits I was using negative lookbehind, which
are only available in Ruby 1.9+.
Rewritten using a different logic which now works on both versions
of Ruby
(#2437) For ruby 1.9, always consider input text as ASCII
(maint) Move setup steps into a subdirectory for jenkins

This will make space for setup steps for local standalone vms.
(maint) Setup files used for acceptance runs on local vms
(maint) Vagrantfile and ssh keys for acceptance runs against local vms
(maint) Obtain options/config specific to jenkins ci run
(maint) Isolates the ci specific tasks within that namespace.
(maint) Added rake commands for standalone acceptance runs

Configuration separated into config/jenkins config/local and
config/options.rb handles mergeing defaults for the two different run
modes.
(maint) Removes non-existent rake target.

qa_ssh_key target is not implemented currently (see README)
(maint) Clarify SHA environment variable for ci:test