Merge branch 'iet-ou/CR21/url-field' of github.com:IET-OU/wp-evidence-hub
Merge branch 'master' of https://github.com/mhawksey/wp-evidence-hub
Merge github.com:IET-OU/wp-evidence-hub
Merge https://github.com/IET-OU/wp-evidence-hub
Bug #28, Fix for broken tag URLs - put evidence content in archives [LACE]
Bug #29, Fix CSS for primary nav floating under the evidence map [LACE]
Bug #29, Follow-up for CSS style fix
Bug #30, Re-factor "wp_evidence_hub" PHP - part 1 [LACE]

* Extend a base class containing utilities and WordPress wrappers
Bug #31, Re-wrote "get_custom_post_type_template()" function.. [LACE]

* ...To hopefully be more fault tolerant - hypothesis issue
* Plus, added `*_Base->message()` and `debug()` functions
Bug #30, Re-factor "wp_evidence_hub" PHP - part 2 [LACE]
"isset()" fix to custom post-type base class PHP [LACE]
Bug #31/ #33, Fix for [hypothesis_summary] shortcode - the_excerpt [LACE]

* Fix for unintentional recursion using WordPress `the_excerpt()` function
Bug #24/ #30/ #33, Make shortcode classes extend `Evidence_Hub_Base` [LACE]

* Plus, explicit Javascript warning if `dt_totals` is not defined
* Split [hypothesis_balance] WP shortcode PHP into two functions
Bug #30, Re-factor [hypothesis_summary] shortcode
Bug #30, Fix stray apostrophe ( ' ) in re-factor [LACE]
Bug #31/ #33, Fix "Undefined variable: post" PHP notice [LACE]

* Plus, formal WP apply_filters( 'hypothesis_excerpt' ..)
Bug #35, SVG map too small on hypothesis pages - CSS min-height [LACE]
Bug #18, Display an error - safely get json-decoded properties.. [LACE]

* Follow-up - WP shortcode:  [evidence_summary]
Bug #36, Fix for 'broken' evidence permalinks on LACE [LACE]

* Add a configuration option, 'EVIDENCE_POST_TYPE_NO_REWRITE'
* Moved 'get_option()' function to Evidence_Hub_Base class
* Custom post-type(s) now extend common '*_Base' class
Small fixes/ edits