New header style & started the responsive styling

Updated the style of the header to make it more organised and provide a
better layout for all screen sizes. I also have started to make the
website more responsive by implementing a grid system and screen
breakpoints.

* Change the style of the header for a cleaner look
* Added a grid system (unsematic)
* Added a mobile navigation that shows when on small mobile like screens
* The banner changes sizes when on tablet sized screens.
* The three unique sections are now in a grid of three.
Continued to make website responsive

I have improved the look of the three info sections on both mobile and
tablet devices. I have also added a 20px margin-top to the sections to
seperate them from each other and from the top banner.

* Improved look of three info columns on mobile and tablet devices.
* Seperated the three columns from each other and top banner.
Made the about section responsive

The about section has been seperated into two columns on desktop and
tablet devices, then when on mobile device it goes into one paragraph.

* Removed the column styles - is known to have problems + no ie support
* Seperated about into two p tags instead of one
* On desktop and tablet devices there are two columns
* On mobile device the two paragraph tags are changed to behave as one.
Changed colour of seperating borders
Index is now responsive

Finished making the home page, index.php, responsive. The footer now
changes depending on the screen size and if on mobile the social links are
removed. The social section is now also responsive with one going below
the other on tablet and mobile. The contact form is also
responsive with the message being next to other elements untill the size
is mobile like then the form is one after the other. Finally, when the
contact input field is active it has an orange border to match the rest of
the colour scheme.

* Finished the responsive part of the index.php
* Updated the contact form to have border when field is active.
* Changed the style of the send button so the font is now styled correctly
Finished making website responsive

Made the article.php and portfolio.php pages responsive. Made the css file
more organised as sections were all over the place.

* article.php and portfolio.php now responsive
* Made the css file more organised.
Merge remote-tracking branch 'upstream/master' into add-responsive
Responsive stuff has been completed.

The responsive re-write has finished with all current pages being
responsive. May need to edit members.php when more members are added.