StringTemplate - alternative syntax for tokens

[VitaliyMF]

Currently token placeholders allow only [a-z_-] chars, 2 issues with this:

• in some rare cases it might be a need to specify any token name
• it is not possible to use "-" or "" after a token name - for example in this template: `@date@time- here 1st token is "date_" and no way to place_` without an additional space after token's placeholder

Both these issues may be fixed by introducing an alternative placeholder's format (similar to .NET MVC Razor):

@(<any_chars_except_closing_braket>)

for example @(date)_@time

[VitaliyMF]

Shipped in 1.2.7