Better timeseek on resume files

Timeseek was broken with resume files:
-When a resume file was started, it returned 00:00:00 position to
renderer, making very difficult to someone to know what position the
resume seeks to, because renderer thinks it's playing from the beginning
-If someone wants to seek the file, it's necessary to use relative
position, because 00:00:00 in player was the resume position, which is
very annoying
-If someone stops playing the resume file before it ends, UMS will
record the relative position, not the real position in file
Moved timeseek logic

Moved timeseek logic to occur before getInputStream(), now it really
does the real thing, not just set the headers.
Cosmetic corrections

Reverting some little past changes that are not necessary anymore.
Merge pull request #276 from tdcosta100/better-timeseek-resume

Better timeseek on resume files