resolves #886 add time range anchor to video element
Merge pull request #887 from mojavelinux/issue-886

resolves #886 add time range anchor to video element
ignore .idea folder used by RubyMine
remove redundant character escapes in regexps
fix spelling error
refactor unit tests so they work in RubyMine

- explicitly add the test and lib directory to the load path
- switch to the project root before running tests
- add UTF-8 encoding magic header to all test files
- exclude .gem file at root of project (where RubyMine puts it)

This commit was modified from the original pull request by @mojavelinux
fix typo in capture group var assignment
resolves #878 use glyphs for checkboxes when not using font icons
Merge pull request #893 from mojavelinux/issue-878

resolves #878 use glyphs for checkboxes when not using font icons
use $~[0] instead of $& for Opal compatibility
add support for resolving includes under Opal
Merge pull request #895 from mojavelinux/asciidoctorjs-includes

add support for resolving includes under Opal
qualify RUBY_ENGINE_OPAL constant
resolves #896 rescue failure to resolve ::Dir.home
resolves #804 rewrite extensions to support extension instances

- rewrite extensions to support extension instances
  - class names, class instances and blocks are supported for every kind of extension
- document extension APIs
- introduce DSL for configuring extensions
- add named group registration
- add require library flag, -r, to cli for custom requires
- add convenience methods on extension processor for creating various nodes
- support lamba as process method
- move all DSL methods to DSL classes
- allow extension group or extensions registry to be passed to document
- rename name dsl method to named; add helper method to parse content
- refactor extension in Rakefile to work with new extension API
- document extension APIs, use methods to retrieve all extensions
- add default content model map to simplify Block creation
- allow subs to be overridden in block constructor
- add content_model option for macros to disable attribute parsing
- allow empty target for block macro
- add name_positional_attributes alias to pos_attrs option
- rename methods to import dsl, update docs
- don't output style on open block if nil, add missing endlines
- pass attributes to Processor#parse_content
- clear attributes if no block is dropped, update default content model map
- duplicate attributes passed to processor; change return nil to return
- add create method for example
- add caption based on presence of <context>-caption attribute
- move image postprocessing to generic location
- add extension tests and docs
- optimizations:
  - replace more calls to .nil? with truth checks
  - remove duplicate lookup of source in constructor
  - optimize caption assignment
  - cache path resolver
  - change order of truths in reader and document
Merge pull request #890 from mojavelinux/issue-804

resolves #804 rewrite extensions to support extension instances
call each thing by its right name

- rename Lexer to Parser
- use dot notation instead of double colon notation for class methods
Merge pull request #899 from mojavelinux/lexer-to-parser

call each thing by its right name
resolves #554 switch default docbook backend to docbook5

- switch docbook backend to docbook5.
- make tests for DocBook 4.5 specify the correct backend
- update documentation to reflect new docbook backend
resolves #554 make docbook45 templates inherit from the docbook5 templates