Request: More global options

[jmbarbone]

Specifically these come to mind for addWorksheet, writeData, and writeDataTable

• showGridLines
• tabColour
• borders
• borderColour
• borderStyle
• tableStyle
• headerStyle
• withFilter
• na.string
• firstColumn
• lastColumn
• bandedRows
• bandedCols

... or essentially anything else that could be used for formatting.

Further, the default options could be saved in an exported op.openxlsx for reference. If that is used, then the default options can be set globally with .onAttach() and a wrapper for getOptions() specifically for openxlsx can be used to simplify each of the calls. I'd expect that all of the calls to these would have to be reviewed to make sure that the global options set are checked first.

[jmbarbone]

FYI I've made some progress on this here: master...jmbarbone:165-options

There are more options I saw that could benefit from having default global settings than the short list above. Although it may seem like a lot, this should be easy enough for someone to set all the specific global options they need in a named list and pass that to options() (or, a safer function that checks that the option is valid). Still WIP. Some of the values are not consistent between functions so ideally the default global option will not change this.