Header lines without a period are discarded unnecessarily

[kinverarity1]

Is your feature request related to a problem? Please describe.
Frustrating when erroneous LAS header section lines like this are discarded and therefore unavailable for parsing:

   ##   Unique Well Identification ##
           HOLE NUMBER :CEM146
   ##  Drilling Information  ##
              DRILLED  :12/11/2010

Describe the solution you'd like
For lines such as those above (i.e. missing a period, but including a colon), parse them as containing only a mnemonic and a value.

Describe alternatives you've considered

Additional context