Element-android: Text Composer: slash commands

[manuroe]

The editor must manage slash command:

• [x] manage completion
• [x] display help
• [x] convert the command into action

(legacy) commands to handle

• [x] "/me"
• [x] "/ban"
• [x] "/unban"
• [x] "/op"
• [x] "/deop"
• [x] "/invite"
• [x] "/join"
• [ ] "/part"
• [x] "/topic"
• [x] "/kick"
• [x] "/nick"
• [x] "/markdown"
• [ ] "/clear_scalar_token"
• [ ] "/myroomnick"
• [ ] "/myroomavatar"
• [x] "/rainbow"
• [x] "/rainbowme"
• [x] "/shrug"
• [ ] "/rainbowshrug"

[jtagcat]

/rainbow
/shrug
/rainbowshrug
;)
There should also be better markdown handling, if there isn't an issue for it.

[fbruetting]

May it be useful to create pills out of for example /me?

Currently (v0.10.0) it also makes no difference for the room preview in the room overview. So /me is going and just is going are both rendered as Frank– is going. Shouldn’t the first be shown as Frank– Frank is going (or maybe just Frankis going)?

[bpcurse]

What about /plain?
It is quite helpful if you want to demonstrate the use of markdown and it's only temporary.

[bmarty]

The slash commands list on RiotWeb is growing too fast :)

[bmarty]

Support for /plain command is in #1093 :)

[Fidgetcetera]

also chiming in for /myroomnick and /myroomavatar, which are very nice to have.

[bmarty]

I updated the list