t: move common code into utils library
WrappedParser: make cell format storage less dumb

 * I had been precalculating the format objects for each cell by
   figuring out which of the cell, row, and column formats applied, and
   saving that format object.  This worked, but made it hard to test
   spreadsheets for expected columns, since it meant that every single
   cell got an explicit format set.  Because of this, cells that had
   previously been undef and got their formatting fro row or column
   defaults were now extant w/ a value of ''.

   Now I just store the cell-specific format ids and provide the
   get_computed_cell_format() method to calculate the displayed format.
CloneXLSX: save row formats
t: update cell_bgcolors_are to use computed format
t: fix up cell contents test for 03-clonexlsx.t
CloneXLSX: small pod updates
Checking in changes prior to tagging of version 0.02.

Changelog diff is:

diff --git a/Changes b/Changes
index 0532fe4..acd00a7 100644
--- a/Changes
+++ b/Changes
@@ -2,6 +2,15 @@ Revision history for Perl extension Excel-CloneXLSX

 {{$NEXT}}

+0.02 2014-08-11T12:39:00Z
+
+    - start saving row formats
+    - smarten up format storage:
+      - save cell format numbers instead of objects
+      - add get_computed_cell_format() to calculate format
+        precedence
+    - improve tests, add testing library
+
 0.01 2014-08-08T16:19:52Z

     - original version