File dialog selects file in working directory over selected one

[angryzor]

When selecting a file with the same name as a file in the running application's current working directory, the check at

ImGuiFileDialog/ImGuiFileDialog.cpp

Line 2587 in 16fc5d6

if (m_FileSystemPtr != nullptr && m_FileSystemPtr->IsFileExist(filename)) {

will naively assume that filename is an absolute path, and it will return the file from the application's working directory instead of the actually selected file.

[aiekick]

i see.

related to #144

[aiekick]

just fixed