#1315. Add option to display week number on calendar

[LukashonakV]

Config example:
"clock": { // "timezone": "America/New_York", "format": " {:%b %d %Y (%R)}", "tooltip-format": "<big>{:%Y %B}</big>\n<tt><small>{calendar}</small></tt>", "format-alt": "{:%Y-%m-%d}", "today-format": "<span color='#ff6699'><b><u>{}</u></b></span>", "week-pos": "left", "week-format": "<span color='#99ffdd'><b>{}</b></span>", "interval": 10 }
Screenshots:

[LukashonakV]

Prints weeknum on the left side for the first row

[LukashonakV]

• calendar day-of-week header is misaligned in Chinese #1321
  Added custom user formats for the: calendar, calendar week numbers, calendar week days
  Config example: "clock": { // "timezone": "America/New_York", "format": " {:%b %d %Y (%R)}", "tooltip-format": "<big>{:%Y %B}</big>\n<tt><small>{calendar}</small></tt>", "format-alt": "{:%Y-%m-%d}", "today-format": "<span color='#ff6699'><b><u>{}</u></b></span>", "calendar-weeks-pos": "left", "format-calendar": "<span color='#ecc6d9'><b>{}</b></span>", "format-calendar-weeks": "<span color='#99ffdd'><b>{}</b></span>", "format-calendar-weekdays": "<span color='#ffcc66'><b>{}</b></span>", "interval": 10 },
  Screenshots:
  

[Alexays]

LGTM thx!

[tmpm697]

Can we use different LC_TIME for it (when display {calendar})? As the language to display will depends on it.