refactor: do not use dynamic allocation where not needed

feat: add directory list

fix: some file access function types

fix: malloc error handling

feat: add file execute process

feat: add local file access functions

fix: add include guards to path

refactor: fix inconsistency in file access function definitions

feat: add structure for dynamic file access

refactor: remove unnecessary libraries linked

refactor: use libmagic even for ppm

feat: add file browser base

refactor: use libmagic instead of custom handling magic numbers

refactor: add gitignore to docs

docs: move doc to user manual

docs: add date

docs: make appropriate code modifiers

refactor: cleanup build flags

fix: includes for jpeg

docs: add manual and and compilation documentation