Merge branch 'develop' of https://github.com/closedxml/closedxml into issue328-indexoutofrangeexception ...

# Conflicts:
#	ClosedXML_Tests/Resource/Examples/Misc/Collections.xlsx
#	ClosedXML_Tests/Resource/Examples/Misc/Formulas.xlsx
#	ClosedXML_Tests/Resource/Examples/Misc/Hyperlinks.xlsx
#	ClosedXML_Tests/Resource/Examples/PivotTables/PivotTables.xlsx
#	ClosedXML_Tests/Resource/Examples/Ranges/NamedRanges.xlsx

Update test files. All .xml files now start with 1, i.e. no more sheet.xml (without digit). Digits now also decimal based, not hexadecimal.

Add extension method to wrap sheet name in quotes, only if required, i.e. it contains a space in the name ...

Throw exception of invalid named range is added on workbook scope
Contain named range references to minimum and maximum column and row dimensions when deleting rows / columns. Fixes #328

Look at both worksheet autofilter as well as table autofilters to determine to leave space for arrow

Implement 'Visible' property on named ranges. Fixes #106

Add test

Fix XLColor equals method (#25) ...

* Use ToArgb() to compare equality of colors, in order to return TRUE when comparing RGB(FF,FF,FF) to White.
http://stackoverflow.com/questions/8146453/system-drawing-color-equality-operator-doesnt-treat-0xffffffff-as-color-white

* Add test for named color vs RGB

* Update bespoke unit tests files to remove duplicate font styles.

* Set substringo of rich text to Garamond font, instead of Broadway. Broadway probably isn't installed on the AppVeyor server. Garamond is a much more common pre-installed font.

* Disable different font to see if it affects the AppVeyor build.

* Use Courier font for rich text. Hopefully this one is installed on AppVeyor.

Project hierarchy cleanup