[wp-polyglots] Last Call for 1.5.1 String Updates

[Mihailo Stefanovic]

> If you see any strings that need to be fixed, speak now. 1.5.1
> approacheth.

Hello Ryan,

While working on Serbian translation, I've noticed several (semi-)duplicate
strings, as well as some inconsistencies in original POT that perhaps could
be eliminated.

First, there is an issue of word "e-mail": sometimes it is spelled as
"e-mail", sometimes as "email". Then, there is "e-mail:", "E-mail",
"E-mail:", "E-mail: %s", "E-mail : %s", and so on.

Second, error messages. In most cases they start with
"<strong>ERROR</strong>:", but in three, there is only "Error:".

And to combine it:

Error: please enter a valid email address
<strong>ERROR</strong>: Please type your e-mail address.
<strong>ERROR</strong>: please type your e-mail address
<strong>ERROR</strong>: please type an e-mail address

(notice that sometimes words after ":" start with upper case, sometimes with
lower, creating duplicate strings in some cases).

And there is this issue: "You are about to delete...". Sometimes it is: 
" \\'OK\\' to delete, \\'Cancel\\' to stop.", and sometimes:
"\\'Cancel\\' to stop, \\'OK\\' to delete.". And of course, there is:
"OK to delete, Cancel to stop" (without quotes).

If it was up to me, I'd split all those strings into two parts ("you are
about to..", and "OK to...")

And should we really use single quotes ('OK') when double quotes seem to be
used for everything else?

I'm sorry, but I've been too busy (or too lazy 0:)) to properly file this
issues in Mosquito.