Accept multiline string continuation

[mingodad]

With this patch squirrel can accept multiline string continuation like C/C++/Shell:

local str = "one line \
with continuation";
print(str);

[zeromus]

Both looks good to me, and small simple fixes.

[RizzoRat]

Multiline: Like it, but does not take into account \r\n endings (windows for example). You'd need to specifically filter for both cases. (Sorry, didn't have the time to read the enums patch)