Fix #41. Aliases not working

lib/term.js

@@ -64,9 +64,17 @@ class Term {
 
 function updateRegExp(term) {
 
+    const termAndAliases = [...term.aliases, term.term];
     let flags = "u";
-    let regExp = `(${term.term}`;
-    term.aliases.forEach(alias => regExp += "|" + alias);
+    let regExp = `(`;
+
+    // A shorter term may be a substring of a longer term which causes issues
+    // when the regExp is used to split a text block (see #41). Thus we sort
+    // sort by length descending to create a regExp which tests for the longest
+    // term first.
+    termAndAliases
+        .sort((term1, term2) => term2.length - term1.length)
+        .forEach((alias, idx)  => regExp += (idx > 0 ? "|" : "") + alias);
     regExp += `)`;
 
     if (term.ignoreCase) {