Add Repeat Hole Stmt and fix UnitStmt parsing

* Repeat hole support (with no real parsing, just a copy)
* Fix UnitStmt to works even when a ,TZ or ,LZ information is not provided.

gerber/excellon.py

@@ -204,8 +204,7 @@ class ExcellonParser(object):
             self.statements.append(DrillModeStmt())
             self.state = 'DRILL'
 
-        elif (('INCH' in line or 'METRIC' in line) and
-              ('LZ' in line or 'TZ' in line)):
+        elif 'INCH' in line or 'METRIC' in line:
             stmt = UnitStmt.from_excellon(line)
             self.units = stmt.units
             self.zero_suppression = stmt.zero_suppression
@@ -244,6 +243,10 @@ class ExcellonParser(object):
                 self.active_tool = self.tools[stmt.tool]
             self.statements.append(stmt)
 
+        elif line[0] == 'R' and self.state != 'HEADER':
+            stmt = RepeatHoleStmt.from_excellon(line, self._settings())
+            self.statements.append(stmt)
+
         elif line[0] in ['X', 'Y']:
             stmt = CoordinateStmt.from_excellon(line, self._settings())
             x = stmt.x

gerber/excellon_statements.py

@@ -29,7 +29,7 @@ __all__ = ['ExcellonTool', 'ToolSelectionStmt', 'CoordinateStmt',
            'RewindStopStmt', 'EndOfProgramStmt', 'UnitStmt',
            'IncrementalModeStmt', 'VersionStmt', 'FormatStmt', 'LinkToolStmt',
            'MeasuringModeStmt', 'RouteModeStmt', 'DrillModeStmt', 'AbsoluteModeStmt',
-           'UnknownStmt',
+           'RepeatHoleStmt', 'UnknownStmt',
            ]
 
 
@@ -280,6 +280,22 @@ class CoordinateStmt(ExcellonStatement):
         return '<Coordinate Statement: %s>' % coord_str
 
 
+class RepeatHoleStmt(ExcellonStatement):
+
+    @classmethod
+    def from_excellon(cls, line, settings):
+        return cls(line)
+
+    def __init__(self, line):
+        self.line = line
+
+    def to_excellon(self, settings):
+        return self.line
+
+    def __str__(self):
+        return '<Repeat Hole: %s>' % self.line
+
+
 class CommentStmt(ExcellonStatement):
 
     @classmethod
@@ -478,6 +494,9 @@ class UnknownStmt(ExcellonStatement):
     def to_excellon(self, settings=None):
         return self.stmt
 
+    def __str__(self):
+        return "<UnknownStmt: %s >" % self.stmt
+
 
 def pairwise(iterator):
     """ Iterate over list taking two elements at a time.