Here we documents all class specification commands available inside of
the class definition script argument of [cmd ::critcl::class::define].

[subsection {General configuration}]          [include include/class_spec_general.inc]
[subsection {Class lifetime management}]      [include include/class_spec_clife.inc]
[subsection {Instance lifetime management}]   [include include/class_spec_ilife.inc]
[subsection {Class variables and methods}]    [include include/class_spec_cvarm.inc]
[subsection {Instance variables and methods}] [include include/class_spec_ivarm.inc]
[subsection {Context dependent interactions}] [include include/class_spec_cdin.inc]