Remove brackets from ini_setting titles to workaround PUP-4709

[domcleal]

Puppet 4.0 and 4.1 are affected by PUP-4709 which raises duplicate
resource errors when using create_ini_settings(), due to the inclusion
of square brackets in the resource titles.

Error while evaluating a Function Call, Duplicate
declaration: Ini_setting[[foo] bar] is already declared; cannot
redeclare

Removing these from the function allows it to work on these Puppet
versions without error.

Replaces #195.

[bmjen]

Thanks @domcleal !

[cdenneen]

There are cases where the setting can be used more than once and a resource title of res["#{path} #{section} #{setting}"] wouldn't work in the case where you'd have something like:

[profile "home"]
source = /home/me
source = /root
exclude = .backup
exclude = .secretsauce

Is there anyway anyone can think of a way to make this work? Most of the ways I am thinking of could potentially leave bad entries say if you "update" a value later... it will just create a new one.