switch facility head skill gain to increaseSkill() function

src/endWeek/healthFunctions.js

src/endWeek/reports/brothelReport.js

src/endWeek/reports/cellblockReport.js

src/endWeek/reports/clinicReport.js

src/endWeek/reports/clubReport.js

src/endWeek/reports/dairyReport.js

src/endWeek/reports/farmyardReport.js

src/endWeek/reports/nurseryReport.js

src/endWeek/reports/penthouseReport.js

src/endWeek/reports/schoolroomReport.js

src/endWeek/reports/servantsQuartersReport.js

src/endWeek/reports/spaReport.js

src/endWeek/saBeYourHeadGirl.js

src/endWeek/saGuardYou.js

src/endWeek/saRecruitGirls.js

src/endWeek/saTakeClasses.js

src/js/economyJS.js