rest: match paths using regexp

Adds regex pattern matching on paths, so path variables could be more
complex that are now.

Here are some examples
```
/r/users/:id{\d+}
```

will match only

```
/r/users/123
```

but not

```
/r/users/john
```

sitebricks/pom.xml

@@ -14,7 +14,7 @@
     <dependency>
       <groupId>org.testng</groupId>
       <artifactId>testng</artifactId>
-      <classifier>jdk15</classifier>
+      <version>6.1.1</version>
       <scope>test</scope>
     </dependency>
     <dependency>

sitebricks/src/main/java/com/google/sitebricks/routing/PathMatcherChain.java

@@ -3,7 +3,12 @@
 import net.jcip.annotations.Immutable;
 import org.jetbrains.annotations.NotNull;
 
-import java.util.*;
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.regex.Pattern;
 
 /**
  * @author Dhanji R. Prasanna ([email protected])
@@ -23,7 +28,15 @@ private static List<PathMatcher> toMatchChain(String path) {
 
         List<PathMatcher> matchers = new ArrayList<PathMatcher>();
         for (String piece : pieces) {
-            matchers.add((piece.startsWith(":")) ? new GreedyPathMatcher(piece) : new SimplePathMatcher(piece));
+            if (piece.startsWith(":") && piece.contains("{") && piece.contains("}")) {
+                String name = piece.substring(0, piece.indexOf("{"));
+                String pattern = piece.substring(piece.indexOf("{") + 1, piece.lastIndexOf("}"));
+                matchers.add(new RegExPathMatcher(pattern, name));
+            } else if (piece.startsWith(":") && !piece.contains("{")) {
+                matchers.add(new GreedyPathMatcher(piece));
+            } else {
+                matchers.add(new SimplePathMatcher(piece));
+            }
         }
 
         return Collections.unmodifiableList(matchers);
@@ -117,6 +130,33 @@ public String name() {
         }
     }
 
+    @Immutable
+    static class RegExPathMatcher implements PathMatcher {
+        private final Pattern pattern;
+        private final String variable;
+
+        public RegExPathMatcher(String pattern, String piece) {
+            this.pattern = Pattern.compile(pattern);
+            this.variable = piece.substring(1);
+
+        }
+
+        @Override
+        public boolean matches(String incoming) {
+            return pattern.matcher(incoming).matches();
+        }
+
+        @Override
+        public String name() {
+            return variable;
+        }
+
+        @Override
+        public Map<String, String> findMatches(String incoming) {
+            return Collections.emptyMap();
+        }
+    }
+
     //matches nothing, i.e. always returns false (used for blocking sitebricks)
     @Immutable
     static class IgnoringPathMatcher implements PathMatcher {

sitebricks/src/test/java/com/google/sitebricks/routing/PathMatcherTest.java

@@ -76,6 +76,12 @@ public Object[][] getVarPathsAndMatches() {
                 put("title", "sokdoasd");
                 put("id", "aoskpaokda");
             }}, },
+            {"/wiki/:id{\\d+}", "/wiki/123", new HashMap() {{
+                put("id", "123");
+            }},},
+            {"/wiki/:id{[a-z]+}", "/wiki/hello", new HashMap() {{
+                put("id", "hello");
+            }},},
         };
     }