add png logo file

See merge request !26

bugfix: move spiderfy active message into the correct <div> tag. :man_facepalming:

See merge request !25

enhancement: small message in top center of map when the spiderfy effect is active.

See merge request !24

bugfix: Fix loading order

See merge request !23

enhancement: overlaping markers "spiderfy" out when clicked on.

Closes #19

See merge request !22

Overlaping and nearby markers will "spider" out into a circle or spiral when zoom level is 12 or more (pretty zoomed in)
Overlapping markers have the popup disabled until they are popped out and "spiderfied", after that you can click on the individual markers and get the popup info as normal.
Click back on the map a second time to disable the spidering effect.
Current zoom level can be seen in the URL `map_display.php#13/XX.XXXXX/XXX.XXXX` `map_display.php#8/XX.XXXXX/XXX.XXXX` is zoom level 8, etc.
The "spiderfy" effect is currently constrained to zoom level 12 or greater.
This option may become configurable in the settings file if needed. 12 seems a good balance for now.

Fixes #19

bugfix: fixed some php warning messages

See merge request !21

enhancement: manually expire nodes

Closes #18

See merge request !20

ability to manually expire nodes that have not been polled in X amount of *days*

Fixes #18

bugfix: add background colors to the links popup info.

See merge request !19

missed that one during the other popup changes.

forgot to add the icon for the "list view" button... duh!

See merge request kg6wxc/meshmap!5

enhancement: link and button to get back and forth from node_report to the map.

Closes #16

See merge request !18

Fixes #16 just for @ke6bxt :)

change link colors for certain tunnels

See merge request !17

needed for recent changes in the firmware with how OLSR deals with certain interfaces.

enhancement: csv import/export of non mesh markers

Closes #7

See merge request !16

importing and exporting of non mesh markers via CSV file.

also some code cleanup and a few other little changes to admin interface pages that were found during testing.

Fixes #7

enhancement/bugfix: Search for and zoom to node

Closes #11

See merge request !15