Add "Copy to Clipboard" into context menu of Log-Entry

Hi,

I'm using the app to create bug-reports for one of my apps. This requires me to copy the log-entry to clipboard and then add it into my bugtracker. As I could not find any option, to copy a single entry, I modified the app to feature a context menu (instead of a "OnLongListItemClick") which contains the option to copy the entry or use the "old" Search-By filter.
If you like this change, feel free to include it into the app, I think it might help others too.

Greetings

PS: thanks for the app!