#2 Backslashes need escaping in strings

[Paul Williams]

When text strings within parentheses are entered into
the PDF file, they are escaped with a backslash.
However, backslashes themselves need to be escaped.

The solution is as simple as changing the current
substitution regexp from

s|([()])|\\$1|g

to

s|([()\\])|\\$1|g

throughout PDF::Create::Page.

Version: perl-pdf-0.06