(doc) Clarify a couple of comments under lib/puppet/

- 'should not be used in preference to' as 'should be avoided in favor of'
- '25K to 300 symbols to strings' as '25K symbols vs. 300 strings'
(maint) Various fixes (whitespace, etc)
(maint) Spelling fixes for code comments

'acutal' to 'actual'
'allowal' to 'allowable'
'cahe' to 'cache'
'corrosponding' to 'corresponding'
'dafault' to 'default'
'defauls' to 'defaults'
'defualts' to 'defaults'
'follwing' to 'following'
'manageing' to 'managing'
'managhome' to 'managehome'
'matchin' to 'matching'
'pupet' to 'puppet'
'repositry' to 'repository'
'terminii' to 'termini' (per Oxford, 'termini' or 'terminuses')
'ths' to 'this'
(maint) Typo fixes for code comments