add draft of lecture 7
move standart functions from lec6 to lec7
lecture 7 small additions
correcting grammatical errors
hard aligiment of strings
add pointers_and_dyn_mem
index regen
lec_07 edit
minor bug fixes
add two-dim_array_dyn_mem
update two-dim_array_dyn_mem1
index regen
minor bug fix
Merge pull request #15 from razykov/add-lecture-7

Add lecture 7