A configuration file may contain one or more sections to store
multiple settings of the same option. A section is started with a
line that contains a section name enclosed in [ ] and all option settings
that follow are part of that section until the next section is reached.
If the file contains no section names all settings are deposited into
the [DEFAULT] section. If options settings exist before the first
section in a file, those option settings are a part of the [DEFAULT]
section. Simple section names can be considered as keys into a dictionary.
For example:
[DEFAULT] opt1 = v_default [section1] opt1 = v_section1
Can be thought of as:
opt1 = { 'DEFAULT' : 'v_default',
'section1' : 'v_section1' }