config-file based implementation... tons of changes:

- all extraneous files now in lib/
    - default.py contains various defaults needed for program
    - support.py contains most supplemental routines needed for program

- on startup, program makes cache, taglist and config file
    - cache operation is unchanged
    - tags list now supports comments
    - config file allows cache name/size, download directory, tags list,
      and last run date to be changed manually

various cleanups throughout.
Merge branch 'configfile' into develop
Merge branch 'master' into develop

incorporate changes to documentation

Conflicts:
	e621dl.py
pre-stash merge
no more html regex (fixes issue #1)

lots of changes for 2.0.0 release:
+ lib/support:
  + custom arg parsing
  + make and read functions for config/tags
  + cache make/read function
  + SpoofOpen class lives here now

+ lib/default:
  + single location for all non user-editable defaults, such as format
  of empty config file, instructions that go into the tag file, etc.

+ lib/e621_api:
  + get_posts replaces most of previous regex functionality
  + download() lives here too, can be relocated later if there are
  multiple apis other than e621

- regex: deleted
- init_e621dl: deleted

+ e621dl:
  - removed temporary download function
  + additional debug messages
  + downloading loop simplified
  + comments to explain the 3 major steps
Merge branch 'iss1-NoRegex' into develop
merge in donation buttons from documentation
Update README.md
fixed crash on no config file found
Merge branch 'develop' of https://github.com/wwyaiykycnf/e621dl into develop
Merge branch 'develop' for v2.0.0