Update eljlistctrl.cpp

Replaced some incorrect long variables/casts to wxIntPtr. On 64-bit wxIntPtr will be a "long long int" causing compile errors.
Update extra.cpp

Replaced some incorrect long variables/casts to wxIntPtr. On 64-bit wxIntPtr will be a "long long int" causing compile errors.
Merge pull request #6 from Vreugdsoft/patch-2

64-bit fixes.