[NWD] Further EPPlus fixes & improvements (take 2)

- Fix conditional formatting and add a test spreadsheet
- Remove System.Drawing dependency. With this change, the EPPlus
  library has no dependencies outside the base .NET Core library.
- Remove ability to modify most styles

Change-Id: Ida4fc1d946c8b99f7a35cab6ee1eeb503a2d8219
Reviewed-on: https://gnocchi-internal-review.git.corp.google.com/c/third_party/epplus/+/207701
Reviewed-by: Hughes Hilton <hugheshilton@google.com>
47 files changed
tree: 18215cb2841fc930a6decadbf76031840bea0ab6
  1. EPPlus/
  2. NetCoreTests/
  3. .editorconfig
  4. .gitignore
  5. CONTRIBUTING.md
  6. dotnet-csharpier
  7. EPPlus.sln
  8. LICENSE
  9. METADATA
  10. README.md
  11. ReadMe_UpdatingEPPlus.txt
README.md

EPPlus

AppSheet fork of EPPlus

To compile this fork, run: dotnet pack EPPlus/EPPlusSDK.csproj -c Release

Then, copy the .nupkg file: EPPlus/bin/Release/Appsheet.EPPlus.1.0.0.nupkg -> jeenee/lib/nuget