Double quote support for SUMIF()

SUMIF() should handle double quotes properly in both criteria and
cells values. This is especially useful when we need to compare string
containing themselve double quote(s).
Travis: test also against PHP 5.5
Fixed problem in Excel 2007 reader with headers and footers containing multiple images. All images were substituted with the first one.
Number format mask test for dates: test for "General" format should be case-insensitive, and scientific format mask shouldn't return a positive for date
Trap for scientific format masks with "0" or "#" before the "E"
Implement Excel 5 RC4 stream decryption

The decryption functions and objects implemented here are are
based on the source of Spreadsheet-ParseExcel:
http://search.cpan.org/~jmcnamara/Spreadsheet-ParseExcel/
Bugfix: (tavoarcila) Work Item GH-259 - Bug fix reading Open Office files
Merge pull request #244 from Slamdunk/patch-1

Travis: test also against PHP 5.5
Merge pull request #256 from trik/develop

Excel 2007 fail with headers and footers containing multiple images
Merge pull request #228 from PowerKiKi/patch-sumif

Double quote support for SUMIF()
Merge pull request #261 from trvrnrth/excel5CryptoRC4

Add support for reading protected (RC4 encrypted) .xls files
Feature: (trvrnrth) - Add support for reading protected (RC4 encrypted) .xls files (64-bit Linux only)
https://github.com/PHPOffice/PHPExcel/issues/258

CHOOSE() returns "#VALUE!" if the 1st entry is chosen
Bugfix: Work item 20397 - Serious bug in absolute cell reference used in shared formula
Would also have affected insert/delete column/row
Further fix to regexp for preventing update of absolute rows when adjusting row references
Merge pull request #267 from RomanSyroeshko/PHPExcel#258

CHOOSE() returns "#VALUE!" if the 1st entry is chosen
Bugfix: (RomanSyroeshko) Work Item GH-267 - CHOOSE() returns "#VALUE!" if the 1st entry is chosen
General: (dresenhista) Work Item GH-242 - Functionality to getHighestRow() for a specified column, and getHighestColumn() for a specified row
Modified getHighest calls for row/column at Worksheet level to accept optional column/row arguments
When duplicating styles, styles shifted by one column to the right.

PHPExcel_Cell::rangeBoundaries -> PHPExcel_Cell::columnIndexFromString (Column index (base 1 !!!))
PHPExcel_Cell::stringFromColumnIndex Column index (base 0 !!!)