mapvote improvements + randomness fix

[raphael12333]

design improvements fix end of maprotation from never being proposed

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hello

this update proposal uses 1 hudelem per mapname, instead of 1 which merges all mapnames in a multi-line string

pros:

• this allows to use default font which imo looks more elegant than the "fixed" ones, without causing misalignment based on resolutions
• this globally provides more flexibility since each mapname have a .color parameter etc
• no need to worry about the string char limit

cons:

• it requires max 9 more hudelem

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  but it shouldn't be a problem because:

max hudelem = 62 (31 default + 31 .archived = false)

required hudelem: default (archived):

• Countdown
• Header background
• Instructions title
• Vote count title
• Main background
• Map names max 10
• Votes counts max 10 -> 25 max (2 more might be used for codam and miscmod credits) *

non archived:

• Vote indicators max 64 (sv_maxclients) so when reaching 31 clients who vote, the others would have to rely on the obituary to see what they vote for (this is already the case for the current libcod branch mapvote version)

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  here is how it looks:

Please let me know if any modifications are needed for the pull request to be merged

*this should leave at least 4 custom hudelem for the server during mapvote increasing this limit might require client executable file modifications but i'm not sure i should try to make some debug message to appear in console when max hudelem is reached using libcod

Regards raphael