Issue 82 deprecation of classification lookup vlr

[esilvia]

This PR implements #82

Add deprecation notice of the Classification Lookup VLR (§4.1).
Add explicit reference to the VLR wiki.
Standardize references to EVLR and VLR.

This issue was missed during the creation of the v1 public review draft of LAS 1.5

[esilvia]

I just updated the wiki with the following pages:

• https://github.com/ASPRSorg/LAS/wiki/Standard-VLRs
• https://github.com/ASPRSorg/LAS/wiki/User-Contributed-VLRs

The latter page is no longer marked as a draft.

[esilvia]

@kjwaters Can you take a look at the PDF and let me know if that matches your recollection of what we'd planned for #82?

Here's a PDF link of the latest build, including all of the LAS 1.5 changes:
LAS-1.5-issue-82_v3.pdf

I also added the Classification Lookup v2 VLR definition to the wiki here: https://github.com/ASPRSorg/LAS/wiki/Standard-VLRs#classification-lookup-v2