Handle constructing a Value from another Value.

When creating a Value from another Value the new value is used and the
stlyes are combined.

setup.py

@@ -9,7 +9,7 @@
     description="A Python package to ease writing tables of data to Excel",
     packages=find_packages(),
     test_suite="nose.collector",
-    version="0.2.9",
+    version="0.2.10",
     install_requires=["pandas>=0.12.0"],
     extras_require={
         "xlsxwriter": ["xlsxwriter>=0.7.2"],

xltable/table.py

@@ -16,6 +16,10 @@ class Value(object):
     :param xltable.CellStyle: Style to be applied to the cell.
     """
     def __init__(self, value, style=None):
+        if isinstance(value, Value):
+            if value.style:
+                style = value.style + style if style else value.style
+            value = value.value
         self.value = value
         self.style = style