Resolve "[3.0] Drop Room from model"

Closes #192

See merge request !284

Fix error on daily supervisions page

See merge request !289

Merge branch '192-3-0-drop-room-from-model' of edugit.org:AlekSIS/official/AlekSIS-App-Chronos into 192-3-0-drop-room-from-model

Rename ugettext reference

See merge request !288

Resolve "Migrations fail with ProgrammingError"

Closes #195

See merge request !285

Merge branch '187-optimize-rendering-of-substituted-lessons-supervisions-on-daily-lessons-supervisions-page' into 'master'

Resolve "Optimize rendering of substituted lessons/supervisions on daily lessons/supervisions page"

Closes #187

See merge request !282

Resolve "AttributeError: 'NoneType' object has no attribute 'period'"

Closes #196

See merge request !286

Sort supervisions by period

Closes #190

See merge request !287

Resolve "Substitution form allows selecting students"

Closes #191

See merge request !283

Merge branch '186-fix-missing-pre-filtering-and-week-annotation-of-lessonperiods-on-daily-lessons-page' into 'master'

Resolve "Fix missing pre-filtering and week annotation of LessonPeriods on daily lessons page"

Closes #186

See merge request !281

Prepare release 2.5

See merge request !280

Resolve "Supervision Substitution entering"

Closes #185

See merge request !279

Resolve "[UI] Redesign Daily Lessons"

Closes #165

See merge request !276