Fix wildcarding not working properly against content with asterisks

[cjfritz]

Problem:
When a target with unescaped asterisks is matched against a source with escaped asterisks, the source asterisks that are escaped will not match with the asterisks in the target, since '\\*' != '*'. Within the source, asterisks not within the wildcard structure {{*}} must be escaped so they may be ignored by the Matcher object, but will not match with the original unescaped asterisks that they are intended to match.
Solution:
Escape the asterisks within the target as well so '\\*' == '\\*'. Avoid breaking other functionality by checking if the target is undefined or null before generating a new string containing escaped asterisks.
Several tests were added to make sure regular asterisks could be matched, and they did not function as special characters within the Matcher.