add tileOptions() to addRasterImage()

[eduardszoecs]

This is a fix for #507 and deals more generally with tileOptions in addRasterImage().
The issue also links to other related issues in downstream packages.

The PR is backward compatible and raises a deprecation warning for the now overfluous arguments opacity and attribution.

PR task list:

• Update NEWS
• Add tests (if appropriate) [not appropriate? didn't find any existing tests]
• Update documentation with devtools::document()

[eduardszoecs]

but you've directly changed inst/htmlwidgets/leaflet.js which is not the way to go about it.
inst/htmlwidgets/leaflet.js is now auto generated and should not be directly edited. You need to change src/javascript/methods.js and then run grunt build from the project root.

I think this applies also for this PR (sorry for that) :( Will fix asap.

[eduardszoecs]

running grunt build doesn't change anything, so PR is fine (=my manual changes to inst/htmlwidgets/leaflet.js seem to reflect grunt build).

[schloerke]

Hi @Edild

Could you ...

"
2. Ensure that you have signed the individual or corporate contributor agreement as appropriate. You can send the signed copy to jj@rstudio.com.
"
Excerpt from rstudio/httpuv package, which you had no reason to know existed.

Please let me know when you've sent the email. Thank you for your help!

Best,
Barret

[eduardszoecs]

Thanks. Will submit asap - need to check if individual or corporate one applies here.

[eduardszoecs]

@schloerke Done!

[CLAassistant]

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