4,547 Warnings & 10 Errors

Hello CodeIgniters,

I'm new to CodeIgniter, so please forgive my ignorance.

I downloaded CodeIgniter-3.1.5, unzipped it to a new directory and then opened it with Eclipse PDT (Oxygen).

Without writing a single line of code I was presented with 4,547 warnings & 10 errors.
Deleting the User Guide (It uses frames?) reduced it to just 10 errors & 9 warnings. 
(See the two screenshots below.)

Questions:

• Can anyone tell me if these errors are true/false?
  
• Is there any way to resolve these errors?
  
• Is this just a consequence of using Eclipse PDT?
  
• If so, then what's the best IDE to use with CodeIgniter please?
  

Thanks in advance.

Best Regards