meson: add 'default-hinting' option

Fixes #244

conf.d/meson.build

@@ -38,7 +38,7 @@ conf_files = [
   '90-synthetic.conf',
 ]
 
-preferred_hinting = 'slight'
+preferred_hinting = get_option('default-hinting')
 
 conf_links = [
   '10-hinting-@0@.conf'.format(preferred_hinting),

meson.build

@@ -395,3 +395,6 @@ summary({
        'Tests': not get_option('tests').disabled(),
        'Tools': not get_option('tools').disabled(),
        }, section: 'General', bool_yn: true, list_sep: ', ')
+summary({
+       'Hinting': get_option('default-hinting'),
+       }, section: 'Defaults', bool_yn: true, list_sep: ', ')

meson_options.txt

@@ -13,3 +13,7 @@ option('tools', type : 'feature', value : 'auto', yield : true,
   description: 'Build command-line tools (fc-list, fc-query, etc.)')
 option('cache-build', type : 'feature', value : 'enabled',
   description: 'Run fc-cache on install')
+
+# Defaults
+option('default-hinting', type: 'combo', choices: ['none', 'slight', 'medium', 'full'], value: 'slight',
+  description: 'Preferred hinting configuration')