Editing Comma-Seperated Addresses

[OssianEPPlus]

Currently ExcelAddress.Adresses is internal and does not seem to update appropriately in some cases (ConditionalFormatting when read at least)

This makes it overly complex to add a row to both ranges of a comma-separated address, requiring string handling and the creation of new addresses. Potentially we might want to reconsider making the following methods/properties public or creating public-facing alternative methods:

• ExcelAddressBase.AddRow()
• ExcelAddressBase.AddColumn()
• ExcelAddressBase.Insert()
• ExcelAddressBase.Collide()

Potentially we might also want to consider what's been previously discussed: Homogenous handling of addresses via the tokenizer.