Bug #17079 Some startup failure messages are wrong and misleading

Description:
If mysql can see the needed startup files but cannot write to them, it claims that it cannot find the file. It should instead say "I found the file but it has bad permissions or ownership".

If the files in /var/db/mysql/mysql are owned by root and you are starting as user mysql, the log says:

060201 11:43:06 [ERROR] /usr/local/libexec/mysqld: Can't find file: './mysql/host.frm' (errno: 13)
060201 11:43:06 [ERROR] /usr/local/libexec/mysqld: Can't find file: './mysql/host.frm' (errno: 13)
060201 11:43:06 [ERROR] Fatal error: Can't open and lock privilege tables: Can't find file: './mysql/host.frm' (errno: 13)
060201 11:43:06  mysqld ended

How to repeat:
Change the ownership on the files in /var/db/mysql/mysql to root and try to start.

Suggested fix:
Change the error message in two ways:
- Say "I found the file but it has bad permissions or ownership".
- Give the full path to the file that you are failing on. Someone who has just installed MySQL will have no idea where './mysql' is, and you know the path at the point of reporting the error.

The error code 13 gives the right hint "OS error code  13:  Permission denied"
but i agree that this is far from obvious

This trivial error (giving the wrong error message is an error) has not been corrected yet in the 5.x branch. I spent an awful long time scratching my head before noticing the error code. It should be unnecessary for more people to go in the wrong direction when their permissions are to blame