HTML Inline Elements support - whitespace sensitive formatting for inline tags

HTML inline elements are sensitive to whitespace. Previous version of code applied new line to all tags which introduced unwnated whitespace in rendered HTML. I added and modified logic in beautify-html.js to handle these cases.

Change notes include:
- added:   `(array)  Parser.Utils.inline_token` 		- to hold list of HTML inline elements for identification
- added:   `(string)  TK_TAG_INLINE` token` 			- to handle formatting of inline tags specifically
- added:   `(bool)   Parser.found_leading_whitespace` 	- to help with conditional inline tag formatting
- added:   `(bool)   Parser.found_trailing_whitespace` 	- to help with conditional inline tag formatting
- added:   Comments through out the file to help follow flow of data and understand algorithm
- fixed:   Space left when trimming whitespace after "<" inside tag (e.g. `<  tag>`). Now outputs `<tag>`
- changed: `get_token()`, `get_string()`, `get_content()`, and `get_tag()` only return `array[string, string]` (previously `array[string, string]` or just `string`)
- changed: unfinished content (unclosed tags or scripts) now get formatted even when EOF is reached
- todo:    add option to print inline tags on same line as content (inline tags currently get newline if whitespace allows)
- todo:    add indentation formatting for nested inline tags (e.g. `<em>italic <strong>and bold</strong><em>`)
- todo:	   create test driver script with input test cases to track how changes to this file affect final output (regression testing)