Merge pull request #368 from michaelhume/master

Adding support for placeholder on basic text type inputs
- Version 4.3.4
- Fix notice error for oembed field. #365
Don't save empty values for clonable fields. #367
Fix fatal error with T_PAAMAYIM_NEKUDOTAYIM. #370
Version 4.3.5
Allow to register meta boxes via filter
Wrap helper functions into a class
Avoid fatal error on PHP 5.2

Passing func_get_args() directly to call_user_func_array() causes a fatal error in PHP 5.2, which is fixed by first putting the results in a variable.
Merge pull request #373 from alimony/patch-1

Avoid fatal error on PHP 5.2
Version 4.3.6
if no maxFuleUploads defined the dropArea don't have to be hidden

Its either this or you have to make sure it will show up again AFTER
everr file is uploaded.
Also when you upload 8 files and 6 fail, scripts still counts 8 to
determine to hide or show dropArea.
Merge pull request #375 from MikevHoenselaar/master

if no maxFuleUploads defined the dropArea don't have to be hidden
Allow to pass more arguments to "get_terms" function when getting meta value with "rwmb_meta"
Merge branch 'master' of https://github.com/rilwis/meta-box
Allow to add more map options in helper function, using "js_options" param.
Allow to set map type in helper function.
Create new core field and separate field-related functions to field class
New field type: "file_input"
- New field type `image_select`
- Update new syntax for demo.php
Move filter for meta to correct place