Enhancement - related to, but not fixing bug #293

- Added new attribute modifiers 'word' and 'noword' which find the existence
  of whole words, or prove the non-existence of whole words.  If a task has
  the description "Pay the bill", then "description.word:the" will match, but
  "description.word:th" will not.  For partial word matches, there is still
  "description.contains:th".
- Added unit tests for the text.cpp functions.
- Added unit tests including the new modifiers in filters.
- Added unit tests to parse the new modifiers.
- Modified man page.
- Modified the Context::autoFilter processing to use the new modifiers for
  +tag and -tag filtering.
- Added a support email to an error message, while looking at the filter code.
- Added new modifiers to the help report.
- Modified a utf8.t unit test to include an alphanumeric tag, rather than a
  smiley face.

src/tests/att.t.cpp

@@ -33,7 +33,7 @@ Context context;
 ////////////////////////////////////////////////////////////////////////////////
 int main (int argc, char** argv)
 {
-  UnitTest t (95);
+  UnitTest t (97);
 
   Att a;
   t.notok (a.valid ("name"),            "Att::valid name         -> fail");
@@ -146,6 +146,14 @@ int main (int argc, char** argv)
   try {a6.mod ("endswith");} catch (...) {good = false;}
   t.ok (good, "Att::mod (endswith)");
 
+  good = true;
+  try {a6.mod ("word");} catch (...) {good = false;}
+  t.ok (good, "Att::mod (word)");
+
+  good = true;
+  try {a6.mod ("noword");} catch (...) {good = false;}
+  t.ok (good, "Att::mod (noword)");
+
   good = true;
   try {a6.mod ("fartwizzle");} catch (...) {good = false;}
   t.notok (good, "Att::mod (fartwizzle)");