Inconsistent types for line numbers about klogg

[variar]

Opening files with more than UINT32_MAX is broken in klogg as well as upstream. Index builds fine, but line number counter overflows.

[variar]

Klogg uses QString::length and QTextCodec::toUnicode to handle individual strings. So there will be no support for files that have lines with more than 2147483647 characters.

I've decided to keep original limit for total number of lines in file. Files with more than 4294967295 lines will not be displayed correctly.

Klogg uses QIODevice interface to read data from filesystem. This implies that maximum supported file size is 9223372036854775807 bytes (~9223 petabytes). It seems very unlikely to cause any trouble.

I've used stong typing technique from Fluent C++ to express line related types in code (line number, line length, offset and count). This prevents from accidentally passing wrong type (for example, line number instead of number of lines) and allows to limit operations on that types (adding line numbers is not allowed, subtracting line numbers produces a number of lines, but line number can be incremented/decremented etc.).

I hope more old bugs were fixed during this refactoring that introduced.