Update partition size limits and add new recipe for servers in default and efi recipes (bug#1076952)

See discussion in https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1076952

For testing and comments.

Note: You need to disable or increase partman-auto/cap-ram (default 1G) to allow swap size above 1GB.

| part  |  MIN |  PRIO  | MAX |
|-------|------|--------|-----|
| efi   | 768M | 5%free |  1G |
| /boot | 768M | 5%free |  1G |

• "atomic" (all in / filesystem):

| part |  MIN |   PRIO  |   MAX   |
|------|------|---------|---------|
| /    |   5G | 85%free |  unlim  |
| swap | 350M |  5%free | 100%RAM |

• "home" (separated / and /home):

| part  |  MIN |   PRIO  |   MAX   |
|-------|------|---------|---------|
| /     |   4G |  5%free | 100G    |
| swap  | 350M |  5%free | 100%RAM |
| /home |   1G | 80%free |  unlim  |

• "multi" (separated /, /var, /tmp and /home):

| part  |  MIN |   PRIO  |   MAX   |
|-------|------|---------|---------|
| /     |   4G |  5%free | 100G    |
| /var  |   2G |  2%free |  40G    |
| swap  | 450M |  5%free | 100%RAM |
| /tmp  | 500M |  1%free |   3G    |
| /home |   1G | 77%free |  unlim  |

• "server" (separated /, /var, /srv, swap < 1GB):

| part |  MIN |   PRIO  |   MAX |
|------|------|---------|-------|
| /    |   4G |  5%free |  100G |
| /var |   2G |  2%free |   40G |
| swap | 450M |  5%free |    1G |
| /srv |   1G | 78%free | unlim |