lldp: don't try to put speed on an inexistant port
lldp: handle absent lldpRemPortIdSubtype

Closes #22.
snmp: remove unused variable
images: add an image for Juniper EX2200-48T
images: add an image for Juniper EX3300-48T
images: also provide Juniper EX*-24T images

However, since this is not possible to make a distinction just with
sysObjectID, we don't really use them.
misc: update lldpd and wiremaps homepages
datastore: strip out invalid characters by encoding to unicode
git: ignore PID files
images: add Dell PowerConnect 2848
images: add Juniper EX3200 (48T and 24T)
README: provide an example of crontab entry
Moved explored IPs to a different file making it possible to change the list on runtime
Subnets are expanded during execution and not during the reading of the file
Changed tabs to spaces in indentation of previous changes
Merge pull request #24 from arielsalvo/master

Proposed modification - IP list
doc: fix API documentation for "refresh"
doc: rename the API documentation to `API.rst`

This allows GitHub to display the appropriate formatting.
doc: try to fix bad formatting with GitHub
fix: IP ranges in iplist without community are ignored

If one does not have the optional community string for a ip range in the
iplist file that ip range will get ignored.
Merge pull request #25 from tappdarden/master

fix: IP ranges in iplist without community are ignored