Changes in version 0.1.0
-----------------------------------------------------------------------------

* depends on `methods` package
* add `GetOptions` which is the same as `GetoptLong`

Changes in version 0.0.9
-----------------------------------------------------------------------------

* modified tests according to changes of `GlobalOptions` package

Changes in version 0.0.8
-----------------------------------------------------------------------------

* check atomic vector in `qq`
* If the interpolated variable is equal to NULL, it will be converted to "".

Changes in version 0.0.7
------------------------------------------------------------------------------

* vignettes are rendered by knitr
* use `GlobalOptions` package to take care of the global settings
* default value can be set to NULL if it is optional
* if the option is designed as named list and has default value. Elements that are 
  not specified on command-line will be kept with their default values.

Changes in version 0.0.6
------------------------------------------------------------------------------

* default value can be set as a list if the option is specified as opt=[sifo]%

Changes in version 0.0.5
------------------------------------------------------------------------------

* use a global variable which is a flag of whether it is under command-line or not.
* If in interactive session and there is error, the session will be quite while
  throw error instead.


Changes in version 0.0.4
------------------------------------------------------------------------------

* add `cat_prefix` argument in `qqcat` which is prior than `options('cat_prefix')`
  and not globally effective.

Changes in version 0.0.3
------------------------------------------------------------------------------

* If command-line variable is a list, enforce the order of names of elements to 
  be alphabetical (in testing file, tag=%i).
  
* `help` and `version` will not be exported.

Changes in version 0.0.2
------------------------------------------------------------------------------

* add `collapse` option in `qq` so that `qq` can return a vector instead of
  only collapsing them into one string.


Changes in version 0.0.1
------------------------------------------------------------------------------

* the first release
