Update Intro-rus.md
Merge pull request #1 from e-dem/patch-1

Update Intro-rus.md
made perl syntax parser happy
added convenience method uri
added syswrite error checks
fixed sysseek wrong parameter
changed logging levels
added fallback-logger routine
Merge remote-tracking branch 'upstream/master'

Conflicts:
	lib/PEF/Front/Intro-rus.md
Fixed some misprints and added newlines in Intro-rus.md