clone_above_row

• implementing row.clone_above_row(index) - it clones the row above row with index "index". The clone looks exactly like the ofiginal, including all formats and other future features, because it is done on xml level.
• adding some tests (#43) and docs
• easing some dependencies (by @vtamara )

fixes of reported bugs

Thanks to @OlivierB and @RavensKrag for reporting bugs. This realease corrects them.

Flat ODS file format support

gem now supports fods format (just one unzipper xml file). See [GUIDE.md] for more, but basically just open the file Rspreadsheet.open('./test.fods') and work with it as usually.

#42, #43: closing issues

• fix #43 repeated header rows are respected
• fix #42 cells covered by other merged cells are respected

#40: cell formats preperly disconnecting on fly

This fixes issue #40

Upgrading to lates ruby versions (ruby 2.6.3 down to 2.0.0)

This release support for many ruby versions and test for them.

libxml upgrade and some new syntax

• assigement of an value to a cell improved for dates and currencies
• adding rowcount alias
• adding possibility of row[:C] syntax
• upgraded to libxml ver 3.0 (some tests need improvement)
• disabled testing of libxml installed with packaging system instead of gem
• file can be saved to any IO now, making it suitable for creating files on fly.
• basic image handling implemented (issue #24)
• bug corrected: inserted row was not empty, but rather copy of the row below.

Release v0.4.3

• Solving compatibility issues with excel
• datetime improvements

Release v0.4.1 - IO

• Access to document without file creation - IO saving instroduced #7
• saving code massively refactored

Release v0.3 - images

• handeling of images added
• various bugfixes