Set/unset alarms (configurable)

[odin568]

Hi @darkphnx
I have one more feature I need.

As said I want to split with this project one calendar into multiple logical.
There I also need different alarms (as they will be imported to another tool which handles them).

As alarms are something total different than filters, I added a dedicated section.

Not sure if this feature is already going too far for an "ical-filter-proxy".

[darkphnx]

I considered this feature last year, but couldn't get it to work in Google Calendar for some reason so chucked it in the bin. I could certainly use it myself though.

Only comment I have on this PR is do you think we could find a nicer way to express the triggers? I know those are the iCal values, but something more user readable that we can compile would be great.

[odin568]

Hmm... good point. I just saw in the rfc document that also absolute datetime can be defined, so quite flexible. But having a fixed date in our use case attached to all events probably won't make sense.
So in fact we could rely on ISO8601 format. Not sure how to simplify it - format is already quite readable (for techies 😺 ).

So simplest solution would be to add link to documentation about format and to check the format by parsing it into time in order to check if it is technically valid entry

[odin568]

Or we just support i.e. "\d+ days" and "\d+ hours" simply....
And still a full ISO format as now

[odin568]

Implemented something, please have a look @darkphnx

[darkphnx]

I think a solid approach. A little refactoring to tidy up would be great.

[darkphnx]

This is looking good, just onto the nitpicks now, and then some tests.

[odin568]

So then only tests open so far

[odin568]

Added tests, you can also have a look here @darkphnx

[darkphnx]

Beautiful!