changelog for 0.63.0

See merge request !1984

Restructure recruitment navigation

See merge request !1966

I18n

See merge request !1983

see also !1302

attributes: treat empty string as None

Closes #122

See merge request !1981

update non-python dependencies

See merge request !1982

rm exclusion_criteria_checked (only frontend)

See merge request !1956

Fix: "recently contacted" hides important information 2

See merge request !1978

Filter trials

See merge request !1979

Update dependencies

See merge request !1980

optional gender and date of birth in contact form

See merge request !1960

fixes #122

check permission before displaying link to subject detail in guardian item

See merge request !1967

show * for required fields in relevant forms

Closes #127

See merge request !1976