Update devel/lua-penlight to version 1.5.4.

Commits between 1.5.2 and 1.5.4:

* change compat.execute to behave similarly on Lua 5.1 and Lua > 5.1.
* Issue #246: bad/misleading code in examples
* Issue #245 document 'optional'
* split the templating engine in a compile and render step
  backward compatible. Minor caveat is that it introduces
  2 local variables in the template, but chances of name collissions
  are very low.
  Additionally: reduced the string concatenation. Only one concat call
  is left.
* Merge pull request #249 from Tieske/feat/reuse-template
  split the templating engine in a compile and render step
* updated template module
  - added the newline option (for single line output)
  - merged test files: test-template and test-substitute
  - changed compile signature to take a table of options
  - improved error reporting: syntax errors report error + code
* Fix global success variable in lapp.
* Added more tests for seq.last
* Minor refactor of seq.last and fixes corner case of
  an empty source stream as outlined in issue #252.
* Added tests for List.put, remove, len, clear and contains.
* Added tests for List.split.
* Added tests for List.partition.
* Added missing tests for List.range, reduce and foreach.
* feat(template): handle special case of a constant string
  A common scenario is an 'option' for templates, where most
  of the use is without it. This change optimizes the render
  function in case of constant strings
* Fix error in 'pl.lapp.process_options_string'
  Fix error "attempt to concatenate a nil value (local 'vtype')" by
  checking making sure vtype is not nil.
* Merge pull request #250 from Tieske/feat/improve-template
  feat(template) newline option, better error reporting, cleanup
* Merge pull request #255 from doronbehar/patch-1
  Fix error in 'pl.lapp.process_options_string'
* bump version to 1.5.3
* Merge pull request #244 from bungle/master
  change compat.execute to behave similarly on Lua 5.1 and Lua > 5.1.
* Merge pull request #251 from IoriBranford/master
  Fix global success variable in lapp process_default.
* Merge pull request #254 from greatwolf/list_coverage
  List coverage

(alnsn)